Air-conditioning apparatus

ABSTRACT

A cooling device includes a cooling-side intermediate heat exchanger that causes heat exchange to be performed between a heat medium and a cooling refrigerant that flows in a cooling refrigerant circuit. A heating device includes a heating-side intermediate heat exchanger that causes heat exchange to be performed between the heat medium and heating refrigerant that flows in a heating refrigerant circuit. The cooling device and the heating device are connected in series in a heat-medium circulation circuit in which the heat medium circulates.

TECHNICAL FIELD

The present disclosure relates to an air-conditioning apparatus thatcauses heat exchange to be performed between refrigerant that circulatesin a refrigerant circuit and a heat medium that circulates in a heatmedium circuit.

BACKGROUND ART

In the past, an air-conditioning composite system has been proposed thatcan simultaneously condition air and supply hot water (see PatentLiterature 1, for example). In the air conditioning composite systemthat simultaneously condition air and supply hot water, generally, anair-conditioning apparatus and a water heater are connected in parallel,and an air-conditioning temperature and a hot water supply temperaturecan be set individually.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application PublicationNo. 4-263758

SUMMARY OF INVENTION Technical Problem

However, as described in Patent Literature 1, in the case where theair-conditioning apparatus and the water heater are connected inparallel, a large amount of heat remains in return water that flows outfrom the air-conditioning apparatus and the water heater. In an existingair-conditioning composite system, for example, heat recovered by anair-conditioning apparatus cannot be used in a water heater, that is,heat remaining in return water cannot be effectively used. Therefore,the energy efficiency for energy savings in the entire system isreduced.

The present disclosure is applied to solve the above problem of theexisting air-conditioning composite system, and relates to anair-conditioning apparatus that can improve an energy efficiency of theentire system for energy savings.

Solution to Problem

An air-conditioning apparatus according to an embodiment of the presentdisclosure includes a cooling device, a heating device, and aheat-medium circulation circuit in which a heat medium circulates. Thecooling device includes a cooling refrigerant circuit in which coolingrefrigerant circulates, and a cooling-side intermediate heat exchangerthat causes heat exchange to be performed between the coolingrefrigerant that flows in the cooling refrigerant circuit and the heatmedium, and also operates as a condenser in the cooling refrigerantcircuit. The heating device includes a heating refrigerant circuit inwhich heating refrigerant circulates, and a heating-side intermediateheat exchanger that causes heat exchange to be performed between theheat medium and the heating refrigerant that flows in the heatingrefrigerant circuit, and also operates as an evaporator in the heatingrefrigerant circuit. The cooling device and the heating device areconnected in series in the heat-medium circulation circuit.

Advantageous Effects of Invention

According to embodiments of the present disclosure, a cooling device anda heating device are connected in series, a heat medium is caused toflow in the cooling device and the heating device, and the coolingdevice and the heating device use exhaust heat recovered by the coolingdevice and the heating device. It is therefore possible to improve anenergy efficiency for energy saving.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus according to Embodiment 1.

FIG. 2 is a schematic view illustrating an example of the configurationof an indoor unit as illustrated in FIG. 1.

FIG. 3 is a functional block diagram illustrating an example of theconfiguration of a controller as illustrated in FIG. 1.

FIG. 4 is a top cross-sectional view illustrating an example of theconfiguration of a heat-medium flow adjusting valve as illustrated inFIG. 1.

FIG. 5 is a top cross-sectional view schematically illustrating a firststate of the heat-medium flow adjusting valve as illustrated in FIG. 4.

FIG. 6 is a top cross-sectional view schematically illustrating a secondstate of the heat-medium flow adjusting valve as illustrated in FIG. 4.

FIG. 7 is a top cross-sectional view schematically illustrating a thirdstate of the heat-medium flow adjusting valve as illustrated in FIG. 4.

FIG. 8 is a top cross-sectional view schematically illustrating a fourthstate of the heat-medium flow adjusting valve as illustrated in FIG. 4

FIG. 9 is a top cross-sectional view schematically illustrating a fifthstate of the heat-medium flow adjusting valve as illustrated in FIG. 4.

FIG. 10 is a top cross-sectional view schematically illustrating a sixthstate of the heat-medium flow adjusting valve as illustrated in FIG. 4.

FIG. 11 is a schematic view for explaining the flow of a heat medium.

FIG. 12 is a schematic view indicating opening degrees of heat-mediumflow adjusting valves that are associated with the FCUs of a system #1as illustrated in FIG. 11.

FIG. 13 is a schematic view indicating the opening degrees of theheat-medium flow adjusting valves 22 in the case where a FCU is made tobe in a thermo-off state.

FIG. 14 is a schematic view indicating the opening degrees of theheat-medium flow adjusting valves in the case where the FCU performanceof a FCU, which is a representative FCU, varies.

FIG. 15 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus according to Embodiment 2.

FIG. 16 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus according to Embodiment 3.

FIG. 17 is a schematic view indicating a first example of the openingdegrees of the heat-medium flow adjusting valves in the case whererepresentative FCUs in systems #1 to #3 have different FCU performance.

FIG. 18 is a schematic view illustrating a second example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs of systems #1 to #3 have different FCU performance.

FIG. 19 is a schematic view illustrating a third example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs in the respective systems #1 to #3 have differentFCU performance.

FIG. 20 is a schematic view illustrating a fourth example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs in the respective systems #1 to #3 have differentFCU performance.

FIG. 21 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus according to Embodiment 4.

FIG. 22 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus according to Embodiment 5.

FIG. 23 is a flowchart illustrating an example of the flow of processingin the case where heat recovery by a cooling-side intermediate heatexchanger and that by a heating-side intermediate heat exchanger inEmbodiment 5 are not balanced.

DESCRIPTION OF EMBODIMENTS Embodiment 1

An air-conditioning apparatus according to Embodiment 1 of the presentdisclosure will be described. FIG. 1 is a schematic view illustrating anexample of the configuration of an air-conditioning apparatus 100according to Embodiment 1. As illustrated in FIG. 1, theair-conditioning apparatus 100 includes an outdoor unit 1, indoor units2 a to 2 c, and a relay unit 3. The outdoor unit 1 and the relay unit 3are connected by a refrigerant pipe 10, whereby a refrigerant circuit isformed. The indoor units 2 a to 2 c and the relay unit 3 are connectedby a heat medium pipe 20, whereby a heat medium circuit is formed. Theindoor units 2 a to 2 c are connected in series.

[Configuration of Air-Conditioning Apparatus 100] (Outdoor Unit 1)

The outdoor unit 1 includes a compressor 11, a refrigerant-flowswitching device 12, a heat-source-side heat exchanger 13, and anaccumulator 14. The compressor 11 sucks low-temperature, low pressurerefrigerant, compresses the sucked refrigerant into high-temperature,high-pressure refrigerant, and discharges the high-temperature,high-pressure refrigerant. For example, the compressor 11 is, forexample, an inverter compressor the capacity of which is controlled bychanging its operating frequency. It should be noted that this capacityis the amount of refrigerant that is discharged per unit time. Theoperating frequency of the compressor 11 is controlled by a controller 4provided in the relay unit 3, which will be described later.

The refrigerant-flow switching device 12 is, for example, a four-wayvalve, and switches the flow direction of refrigerant to switch theoperation to be performed between a cooling operation and a heatingoperation. During the cooling operation, a flow passage in therefrigerant-flow switching device 12 is switched such that the dischargeside of the compressor 11 and the heat-source-side heat exchanger 13 areconnected to each other as indicated by a solid line in FIG. 1. Duringthe heating operation, the flow passage in the refrigerant-flowswitching device 12 is switched such that the discharge side of thecompressor 11 and the relay unit 3 are connected to each other asindicated by a broken line in FIG. 1. Switching of the flow passage inthe refrigerant-flow switching device 12 is controlled by the controller4.

The heat-source-side heat exchanger 13 causes heat exchange to beperformed between refrigerant and outdoor air that is supplied by, forexample, a fan (not illustrated). During the cooling operation, theheat-source-side heat exchanger 13 operates as a condenser thattransfers heat of the refrigerant to outdoor air to condense therefrigerant. During the heating operation, the heat-source-side heatexchanger 13 operates as an evaporator that evaporates the refrigerantto cool the outdoor air by heat of vaporization produced when therefrigerant is evaporated.

The accumulator 14 is provided on a low-pressure side of the compressor11 that is a suction side of the compressor 11. The accumulator 14separates surplus refrigerant the amount of which corresponds to thedifference between the amount of the refrigerant that flows during thecooling operation and the amount of the refrigerant that flows duringthe heating operation, or surplus refrigerant the amount of whichcorresponds to the difference between the amount of the refrigerant thatflows after a transient change of the operation and the amount of therefrigerant that flows before the transient change of the operation,into gas refrigerant and liquid refrigerant, and then stores the liquidrefrigerant.

(Indoor Units 2 a to 2 c)

FIG. 2 is a schematic view illustrating an example of the configurationof the indoor unit 2 a to 2 c as illustrated in FIG. 1. As illustratedin FIG. 2, each of the indoor units 2 a to 2 c includes a fan coil unit(hereinafter referred to as “FCU”) 21 and a heat-medium flow adjustingvalve 22.

The FCU 21 includes a use-side heat exchanger 121 and a fan 122. Theuse-side heat exchanger 121 causes heat exchange to be performed betweenwater and indoor air that is supplied by the fan 122. As a result,cooling air or heating air is generated as conditioned air to besupplied into an indoor space. The fan 122 supplies air to the use-sideheat exchanger 121. The rotation speed of the fan 122 is controlled bythe controller 4. The amount of air that is supplied to the use-sideheat exchanger 121 is controlled by controlling the rotation speed.

The heat-medium flow adjusting valve 22 is, for example, an electricthree-way valve having an inflow port 22 a, a first outflow port 22 b,and a second outflow port 22 c, and is provided on a water inflow sideof the FCU 21. The heat-medium flow adjusting valve 22 is provided todivide water that has flowed into the heat-medium flow adjusting valve22. The first outflow port 22 b of the heat-medium flow adjusting valve22 is connected to the water inflow side of the FCU 21. The secondoutflow port 22 c is connected to the water outflow side of the FCU 21by an indoor-side bypass pipe 23. Therefore, the second outflow port 22c of the heat-medium flow adjusting valve 22 and the water outflow sideof the FCU 21 are connected.

In this example, in the indoor unit 2 a to 2 c, respective indoor-sidebypass pipes 23 are provided. This, however, is not limiting. Theindoor-side bypass pipes 23 may be provided outside the indoor unit 2 ato 2 c, and connected to the indoor unit 2 a to 2 c by, for example,connection fittings. In such a configuration, the length of theindoor-side bypass pipe 23 is smaller than that in the case where theindoor-side bypass pipe 23 is provided in the indoor unit. It istherefore possible to reduce a loss caused by heat radiation that occurswhen water flows through the pipe. Furthermore, it is not necessarilyindispensable that the indoor-side bypass pipes 23 are provided in allthe indoor units 2 a to 2 c. For example, of the FCUs 21, a FCU 21 orFCUs 21 may be provided with an indoor-side bypass pipe or pipes 23 inthe case where the FCU 21 or FCUs 21 do not need to cause water to flowtherethrough.

In the case where the heat-medium flow adjusting valve 22 includes atleast the inflow port 22 a, the first outflow port 22 b, and the secondoutflow port 22 c, the heat-medium flow adjusting valve 22 may be amulti-way valve such as a four-way valve. To be more specific, forexample, as the heat-medium flow adjusting valve 22, a four-way valvemay be used, and the four-way valve may be used as a pseudo three-wayvalve by using an outflow port other than the first outflow port 22 band the second outflow port 22 c, for other applications, or by closingthe outflow port other than the first outflow port 22 b and the secondoutflow port 22 c in order to inhibit use of the outflow port. It shouldbe noted that as in Embodiment 1, it is optimal that the heat-mediumflow adjusting valve 22 is a three-way valve having a flow rate controlfunction and a block function that can be fulfilled by adjusting theopening degree of the valve, that is, can divide water that flows intothe heat-medium flow adjusting valve 22, while adjusting the flow rateof the water, and that can block each of the divided water. Instead ofusing the heat-medium flow adjusting valve 22, it may be possible touse, for example, a combination of a three-way valve that controls theflow rate and an expansion device that blocks flowing water.Alternatively, for example, at a location between a branch point and ajunction of a pipe provided on the inflow side of the FCU 21 and at theindoor-side bypass pipe 23, respective expansion units may be provided.

Furthermore, each of the indoor units 2 a to 2 c includes an inlettemperature sensor 24, an outlet temperature sensor 25, and a suctiontemperature sensor 26. The inlet temperature sensor 24 is provided onthe water inflow side of the FCU 21 to detect the temperature of waterthat flows into the FCU 21. The outlet temperature sensor 25 is providedon a water outflow side of the FCU 21 to detect the temperature of waterthat flows out of the FCU 21. The suction temperature sensor 26 isprovided on an air suction side of the FCU 21 to detect information onthe temperature of air sucked into the FCU 21.

(Relay Unit 3)

The relay unit 3 as illustrated in FIG. 1 includes an expansion valve31, an intermediate heat exchanger 32, a pump 33, and the controller 4.The expansion valve 31 causes refrigerant to expand. The expansion valve31 is a valve whose opening degree can be controlled, for example, anelectronic expansion valve. The opening degree of the expansion valve 31is controlled by the controller 4.

The intermediate heat exchanger 32 operates as a condenser or anevaporator, and causes heat exchange to be performed between refrigerantthat flows in the refrigerant circuit connected with a refrigerant-sideflow passage and a heat medium that flows in the heat medium circuitconnected with a heat-medium-side flow passage. During the coolingoperation, the intermediate heat exchanger 32 operates as an evaporatorthat evaporates refrigerant to cool a heat medium by heat ofvaporization produced when the refrigerant is evaporated. During theheating operation, the intermediate heat exchanger 32 operates as acondenser that condenses refrigerant by transferring heat of therefrigerant to the heat medium.

The pump 33 is driven by a motor (not illustrated), and circulates waterthat flows through the heat medium pipe 20 and that is a heat medium.For example, the pump 33 is a pump whose capacity can be controlled. Theflow rate of the water that is circulated by the pump 33 can becontrolled in accordance with the load on each of the indoor unit 2 a to2 c. The driving of the pump 33 is controlled by the controller 4. Morespecifically, the pump 33 is controlled by the controller 4 such thatthe greater the above load, the higher the flow rate of water, and thesmaller the load, the lower the flow rate of water.

(Controller 4)

The controller 4 controls the operation of the entire air-conditioningapparatus 100 that includes the outdoor unit 1, the indoor units 2 a to2 c, and the relay unit 3, based on various information that istransmitted from respective units, for example, temperatures atlocations upstream and downstream of respective use-side heat exchangers121 in the air-conditioning apparatus 100, and pressures of a heatmedium at locations upstream and downstream of the pump 33. Morespecifically, the controller 4 controls the operating frequency of thecompressor 11, the driving of the pump 33, the opening degrees of theheat-medium flow adjusting valves 22, the opening degree of theexpansion valve 31, etc. Particularly, in Embodiment 1, the controller 4controls the driving of the pump 33 and the opening degrees of theheat-medium flow adjusting valves 22 based on the performance of theFCUs 21.

The controller 4 is hardware, such as a circuit device, that fulfillsvarious functions, or that fulfills various functions by executingsoftware on an arithmetic unit such as a microcomputer. In this example,the controller 4 is provided in the relay unit 3. This, however, is notlimiting. The controller 4 may be provided in any one of the outdoorunit 1 and the indoor units 2 a to 2 c. Alternatively, the outdoor unit1 and the indoor units 2 a to 2 c may be provided with respectivecontrollers 4.

FIG. 3 is a functional block diagram illustrating an example of theconfiguration of the controller 4 as illustrated in FIG. 1. Asillustrated in FIG. 3, the controller 4 includes an FCU performancecalculation unit 41, a valve opening-degree determination unit 42, avalve control unit 43, a heat-medium flow-rate determination unit 44, apump control unit 45, and a storage unit 46.

The FCU performance calculation unit 41 calculates FCU performance thateach of the FCUs 21 is currently required to achieve. The FCUperformance is the operating performance [kW] of the FCU 21 that isrequired to condition air such that the temperature of the air reaches aset temperature. The FCU performance is calculated based on varioustemperatures detected by the inlet temperature sensor 24, the outlettemperature sensor 25, and the suction temperature sensor 26, and setFCU performance, a set outlet/inlet temperature difference, and a setwater/air temperature difference that are stored in the storage unit 46.

The set FCU performance is FCU performance set in advance for the FCU21. The set outlet/inlet temperature difference is a set temperaturedifference between the outlet temperature of water that flows out of theFCU 21 and the inlet temperature of water that flows into the FCU 21.The set water/air temperature difference is a set temperature differencebetween the temperature of air that is sucked into the FCU 21 and theinlet temperature of water that flows into the FCU 21.

Based on the calculated FCU performance of each FCU 21, the valveopening-degree determination unit 42 determines the opening degree of anassociated heat-medium flow adjusting valve 22. The valve control unit43 produces a control signal for controlling the opening degree of theabove associated heat-medium flow adjusting valve 22 based on theopening degree determined by the valve opening-degree determination unit42, and the valve control unit 43 sends the control signal to theheat-medium flow adjusting valve 22.

The heat-medium flow-rate determination unit 44 determines the flow rateof water that flows into each FCU 21 based on the calculated FCUperformance of each FCU 21. To be more specific, the heat-mediumflow-rate determination unit 44 determines the flow rate of water suchthat the higher the FCU performance, the higher the flow rate of waterthat is made to flow into the FCU 21, and the lower the FCU performance,the lower the flow rate of water that is made to flow into the FCU 21.The pump control unit 45 produces a control signal for controlling thedriving of the pump 33 based on the flow rate of water determined by theheat-medium flow-rate determination unit 44, and the pump control unit45 sends the control signal to the pump 33.

The set FCU performance, the set outlet/inlet temperature difference,and the set water/air temperature differences which are all referred toby the FCU performance calculation unit 41, are stored in advance in thestorage unit 46.

[Configuration of Heat-Medium Flow Adjusting Valve 22]

FIG. 4 is a top cross-sectional view illustrating an example of theconfiguration of the heat-medium flow adjusting valve 22 as illustratedin FIG. 1. As illustrated in FIG. 4, the heat-medium flow adjustingvalve 22 includes a body 22 d having a hollow columnar shape, and theinflow port 22 a that is located at a center portion of an upper surfaceor a bottom surface of the body 22 d. The inflow port 22 a is a portthrough which a heat medium flows into the heat-medium flow adjustingvalve 22. Furthermore, in a side surface of the body 22 d of theheat-medium flow adjusting valve 22, the first outflow port 22 b and thesecond outflow port 22 c through which the heat medium flows out areprovided.

The first outflow port 22 b is connected with the FCU 21, and the secondoutflow port 22 c is connected with the indoor-side bypass pipe 23. Inthe case where the side surface of the body 22 d is divided into regionsarranged at an intervals of an angle of 120 degrees, that is, regionseach curved through an angle of 120 degrees about the center axis, whichis the normal to the upper surface or the bottom surface of the body 22d, the side surface of the body 22 d is divided into the following threeregions: a first region curved from a position corresponding to 0 degreeto a position corresponding to 120 degrees; a second region curved fromthe position corresponding to 120 degrees to a position corresponding to240 degrees; and a third region curved from the position correspondingto 240 degrees to a position corresponding to 360 degrees. The firstoutflow port 22 b is formed in the first region of the above threeregions of the side surface. The second outflow port 22 c is formed inthe second region of the three regions of the side surface.

An opening-degree adjusting valve 22 e having a cylindrical shape isprovided in the internal space of the body 22 d. The opening-degreeadjusting valve 22 e has an opening portion 22 h, which is an openingformed in part of the opening-degree adjusting valve 22 e thatcorresponds to part of an arc cross section thereof, and the openingportion 22 h has a C-shaped cross section. The opening portion 22 hextends in such a manner to curve about the center axis through 120degrees.

In the heat-medium flow adjusting valve 22, a side wall 22 f is providedon an inner periphery of a side surface located in the third region ofthe above divided regions, that is, the first to third regions, suchthat the side wall 22 f has a greater thickness than side surfacesprovided in the first and second regions. The side wall 22 f is providedin such a manner as to contact an outer periphery of the opening-degreeadjusting valve 22 e. Furthermore, a partition wall 22 g is provided onan inner periphery of a side surface located at a boundary portionbetween the first region and the second region such that the partitionwall 22 g contacts the opening-degree adjusting valve 22 e. Thepartition wall 22 g divides water that has flowed into the heat-mediumflow adjusting valve 22 through the inflow port 22 a such that thedivided water flows out from the first outflow port 22 b and also flowsout from the second outflow port 22 c.

The opening-degree adjusting valve 22 e is rotated along the side wall22 f and the partition wall 22 g about the center axis. Since theheat-medium flow adjusting valve 22 is formed in the above manner, flowpassages that each allows water to flow therethrough in accordance witha rotation state of the opening-degree adjusting valve 22 e are providedbetween the inflow port 22 a and the first outflow port 22 b and betweenthe inflow port 22 a and the second outflow port 22 c.

FIGS. 5 to 10 are top cross-sectional views schematically illustratingrespective states in which the opening-degree adjusting valve 22 e ofthe heat-medium flow adjusting valve 22 as illustrated in FIG. 4 isrotated. It should be noted that the opening degree of theopening-degree adjusting valve 22 e that is opened to allow the inflowport 22 a and the first outflow port 22 b to communicate with each otherand thus allow water to flow from the inflow port 22 a to the firstoutflow port 22 b will be referred to as “FCU opening degree”.Furthermore, the opening degree of the opening-degree adjusting valve 22e that is opened to allow the inflow port 22 a and the second outflowport 22 c to communicate with each other and thus allow water to flow tothe second outflow port 22 c through the inflow port 22 a will bereferred to as “bypass opening degree”.

FIG. 5 is a top cross-sectional view schematically illustrating a firststate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. In the first state, the location of the opening portion 22 h of theopening-degree adjusting valve 22 e coincides with that of a regionbetween one end portion of the side wall 22 f and the partition wall 22g. In this case, the opening degree of the heat-medium flow adjustingvalve 22 is set such that the FCU opening degree is 100% and the bypassopening degree is 0%. That is, the flow rate of water that flows outthrough the first outflow port 22 b is 100% of the flow rate of waterthat flows into the inflow port 22 a.

FIG. 6 is a top cross-sectional view schematically illustrating a secondstate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. The second state is a state to which the state of the opening-degreeadjusting valve 22 e is changed from the first state when theopening-degree adjusting valve 22 e is rotated from the position thereofin the first state in a clockwise direction such that the openingportion 22 h of the opening-degree adjusting valve 22 e faces thepartition wall 22 g. In this case, the opening degree of the heat-mediumflow adjusting valve 22 is set such that the FCU opening degree is X %and the bypass opening degree is (100−X) %. That is, the flow rate ofwater that flows out through the first outflow port 22 b is X % of theflow rate of water that flows into the inflow port 22 a. Furthermore,the flow rate of water that flows out through the second outflow port 22c is (100−X) % of the flow rate of water that flows into the inflow port22 a.

FIG. 7 is a top cross-sectional view schematically illustrating a thirdstate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. The third state is a state to which the state of the opening-degreeadjusting valve 22 e is changed from the second state when theopening-degree adjusting valve 22 e is rotated from the position thereofin the second state in the clockwise direction, and in which thelocation of the opening portion 22 h of the opening-degree adjustingvalve 22 e coincides with that of a region between the partition wall 22g and the other end portion of the side wall 22 f. In this case, theopening degree of the heat-medium flow adjusting valve 22 is set suchthat the FCU opening degree is 0% and the bypass opening degree is X %.That is, the flow rate of water that flows out through the secondoutflow port 22 c is 100% of the flow rate of water that flows into theinflow port 22 a.

FIG. 8 is a top cross-sectional view schematically illustrating a fourthstate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. The fourth state is a state to which the state of the opening-degreeadjusting valve 22 e is changed from the third state when theopening-degree adjusting valve 22 e is rotated from the position thereofin the third state in the clockwise direction, and the opening portion22 h of the opening-degree adjusting valve 22 e faces the other endportion of the side wall 22 f. In this case, the opening degree of theheat-medium flow adjusting valve 22 is set such that the FCU openingdegree is 0% and the bypass opening degree is X %. That is, the flowrate of water that flows out through the second outflow port 22 c is X %of the flow rate of water that flows into the inflow port 22 a.

FIG. 9 is a top cross-sectional view schematically illustrating a fifthstate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. The fifth state is a state to which the state of the opening-degreeadjusting valve 22 e is changed from the fourth state when theopening-degree adjusting valve 22 e is rotated from the position thereofin the fourth state in the clockwise direction, and in which thelocation of the opening portion 22 h of the opening-degree adjustingvalve 22 e coincides with that of a region between the above one endportion and the other end portion of the side wall 22 f. In this case,the opening degree of the heat-medium flow adjusting valve 22 is setsuch that the FCU opening degree is 0% and the bypass opening degree is0%. That is, water that flows into the inflow port 22 a is completelyblocked, that is, completely inhibited from flowing out. For example,when space where an indoor unit 2 including a FCU 21 is installed doesnot need to be air-conditioned, the flow of water to the indoor unit 2is blocked by setting the opening degree of the heat-medium flowadjusting valve 22 as illustrated in FIG. 9. Therefore, the load on thepump 33 can be reduced.

FIG. 10 is a top cross-sectional view schematically illustrating a sixthstate of the heat-medium flow adjusting valve 22 as illustrated in FIG.4. The sixth state is a state to which the state of the opening-degreeadjusting valve 22 e is changed from the fifth state when theopening-degree adjusting valve 22 e is rotated from the position thereofin the fifth state in the clockwise direction, and in which the openingportion 22 h of the opening-degree adjusting valve 22 e face the aboveone end portion of the side wall 22 f. In this case, the opening degreeof the heat-medium flow adjusting valve 22 is set such that the FCUopening degree is X % and the bypass opening degree is 0%. That is, theflow rate of water that flows out through the first outflow port 22 b isX % of the flow rate of water that flows into the inflow port 22 a.

In the above manner, the heat-medium flow adjusting valve 22 iscontrolled in opening degree, thereby allowing water that has flowedinto the inflow port 22 a to flow out from both the first outflow port22 b and the second outflow port 22 c at a controlled flow rate.

[Operation of Air-Conditioning Apparatus 100]

Next, the operation of the air-conditioning apparatus 100 having theabove configuration will be described. In the following explanation, theflow of water serving as a heat medium that circulates in the heatmedium circuit and a flow-rate control process in the indoor unit 2 a to2 c are described.

(Flow of heat medium)

FIG. 11 is a schematic view for explaining the flow of a heat medium.Referring to FIG. 11, three indoor units 2 are connected in series inthe air-conditioning apparatus 100. It should be noted that a groupincluding the indoor units 2 connected in series will be referred to as“system”. That is, the air-conditioning apparatus 100 as illustrated inFIG. 11 is configured such that a system #1 includes the indoor units 2a to 2 c connected in series, and the system #1 is connected parallel tothe relay unit 3.

In the relay unit 3, water that has flowed out from the intermediateheat exchanger 32 flows out of the relay unit 3 through the heat mediumpipe 20. The water that has flowed out of the relay unit 3 flows intothe indoor unit 2 a that is located on the most upstream side in thesystem #1.

In the indoor unit 2 a of the system #1, water that has flowed into theindoor unit 2 a flows through an FCU 21 a or the indoor-side bypass pipe23 at a flow rate that depends on the set opening degree of theheat-medium flow adjusting valve 22. The water that has flowed into theFCU 21 a exchanges heat with indoor air to receive heat from or transferheat to the indoor air, thereby cooling or heating the indoor air, andthe water then flows out from the FCU 21 a. The water that has flowedout of the FCU 21 a and the water that has flowed through theindoor-side bypass pipe 23 joins each other at a location downward ofthe FCU 21 a, and flows into the indoor unit 2 b that is provideddownstream of the indoor unit 2 a.

In the indoor unit 2 b, the water that has flowed into the indoor unit 2b flows through an FCU 21 b or the indoor-side bypass pipe 23 at a flowrate that depends on the set opening degree of the heat-medium flowadjusting valve 22. The water that has flowed into the FCU 21 bexchanges heat with indoor air to receive heat from or transfer heat tothe indoor air, thereby cooling or heating the indoor air, and the waterthen flows out of the FCU 21 b. The water that has flowed out of the FCU21 b and the water that flows in the indoor-side bypass pipe 23 joineach other at a location downstream of the FCU 21 b, and flow into theindoor unit 2 c that is provided downstream of the indoor unit 2 b.

In the indoor unit 2 c, the water that has flowed into the indoor unit 2c flows through an FCU 21 c or the indoor-side bypass pipe 23 at a flowrate that depends on the set opening degree of the heat-medium flowadjusting valve 22. The water that has flowed into the FCU 21 cexchanges heat with indoor air to receive heat from or transfer heat tothe indoor air, thereby cooling or heating the indoor, and the waterthen flows out of the FCU 21 c. The water that has flowed out of the FCU21 c and the water that flows in the indoor-side bypass pipe 23 joineach other at a location downstream of the FCU 21 c, and then flow outof the indoor unit 2 c.

The water that has flowed out of the indoor unit 2 c flows into therelay unit 3 through the heat medium pipe 20. The water that has flowedinto the relay unit 3 flows into the intermediate heat exchanger 32 viathe pump 33. Thereafter, the above circulation is repeated.

(Flow-Rate Control Process)

The following description is made regarding a flow-rate control processof adjusting the flow rate of water that flows into the FCU 21 of eachof the indoor units 2 a to 2 c. When water flows into the FCU 21 at arate such that the water causes an air conditioning performance to behigher than a required FCU performance, heat of water cannot be fullyused, and heat remains in water that has passed through the FCU 21.Therefore, a heat usage efficiency for transfer power is reduced.

In view of the above, in Embodiment 1, the air-conditioning apparatus100 performs the flow-rate control process of adjusting the flow rate ofwater for each FCU 21 in the system #1 to cause water to flow into eachFCU 21 at a required flow rate. In the flow-rate control process, theopening degrees of the heat-medium flow adjusting valves 22 that areassociated with the respective FCUs 21 are controlled to adjust the flowrates of water for the FCUs 21.

The flow rate of water that flows into the FCU 21 can be calculatedbased on the difference between the pressure of water before passage ofthe water through the heat-medium flow adjusting valve 22 and that afterpassage of the water through the heat-medium flow adjusting valve 22 anda Cv value indicating characteristics of the heat-medium flow adjustingvalve 22. The Cv value is a value determined based on the type of theheat-medium flow adjusting valve 22 and the diameter of a port of theheat-medium flow adjusting valve 22, and is a capacity coefficient ofthe heat-medium flow adjusting valve 22. The Cv value is a numericalvalue indicating the flow rate of a fluid that passes through theheat-medium flow adjusting valve 22 at a certain differential pressure.The flow rate of water increases as the Cv value increases. The flowrate of water decreases as the Cv value decreases.

The FCU performance calculation unit 41 calculates FCU performance thatthe FCUs 21 in the system #1 are currently required to achieve. The FCUperformance of each FCU 21 is calculated based on formula (1) using setFCU performance set in advance for each FCU 21, an inlet temperature ofwater that flows into the FCU 21, an outlet temperature of water thatflows out of the FCU 21, and the temperature of indoor air sucked by thefan 122.

FCU performance=set FCU performance×(outlet/inlet temperaturedifference/set outlet/inlet temperature difference)×(water/airtemperature difference/set water/air temperature difference)   (1)

In formula (1), the outlet/inlet temperature difference is thetemperature difference between a current outlet temperature of waterthat flows out of the FCU 21 and a current inlet temperature of waterthat flows into the FCU 21. The water/air temperature difference is thetemperature difference between a current temperature of air that issucked into the FCU 21 and a current inlet temperature of water thatflows into the FCU 21.

Next, the valve opening-degree determination unit 42 determines, as arepresentative FCU of the system #1, a FCU 21 having the highestcalculated FCU performance among the FCUs 21 in the system #1. Then, thevalve opening-degree determination unit 42 determines the opening degreeof the heat-medium flow adjusting valve 22 that is associated with therepresentative FCU such that the opening degree is set to the openingdegree of the heat-medium flow adjusting valve 22 opened such that theheat-medium flow adjusting valve 22 is fully opened toward the FCU 21.The valve opening-degree determination unit 42 also determines theopening degrees of the heat-medium flow adjusting valves 22 that areassociated with the FCUs 21 other than the representative FCU based onthe ratios of the performance of the FCUs 21 other than therepresentative FCU to that of the representative FCU.

FIG. 12 is a schematic view illustrating the opening degrees of theheat-medium flow adjusting valves 22 that are associated with the FCUs21 a to 21 c of the system #1 as illustrated in FIG. 11. The FCU numberindicated in FIG. 12 is a number assigned to each FCU 21 in the system#1. In the figure, reference sings denoting the respective FCUs 21 inthe system #1 are indicated; the FCU performance is the FCU performanceof each FCU 21; and the opening degree of the heat-medium flow adjustingvalve is the opening degree of each of the heat-medium flow adjustingvalves 22 that are associated with the respective FCUs 21, and theopening degrees for the FCU 21 and for the indoor-side bypass pipe 23are also indicated.

As illustrated in FIG. 12, of the FCU performance of the FCUs 21 a to 21c in the system #1, the FCU performance of the FCU 21 c is 5 kW, whichis the highest FCU performance in the system #1. Therefore, the valveopening-degree determination unit 42 determines the FCU 21 c as therepresentative FCU of the system #1. Then, the valve opening-degreedetermination unit 42 sets the FCU opening degree of the heat-mediumflow adjusting valve 22 that is associated with the FCU 21 c to 100%,which is the opening degree of the valve opening-degree determinationunit 42 opened such that the heat-medium flow adjusting valve 22 isfully opened toward the FCU 21 c.

On the other hand, the FCU performance of each of the FCU 21 a and theFCU 21 b is 1 kW, which is ⅕ of the FCU performance of the FCU 21 c.Therefore, based on the performance ratio of the FCU performance of eachof the FCU 21 a and 21 b to that of the FCU 21 c, the valveopening-degree determination unit 42 determines that the FCU openingdegrees of the heat-medium flow adjusting valves 22 that are associatedwith the respective FCUs 21 a and 21 b are 20% (=100% x⅕), and thebypass opening degrees of the heat-medium flow adjusting valves 22 are80%.

The following description is made with respect to the case where any ofthe FCUs 21 in the system #1 is made to be in a thermo-off state or thecase where the FCU performance of the FCU 21 varies. The case where theFCU 21 is made to be in the thermo-off state is the case where the fan122 of the FCU 21 is stopped. To be more specific, for example, when anindoor temperature exceeds the set temperature during heating operation,or when an indoor temperature falls below the set temperature duringcooling operation, the FCU 21 is made to be in the thermo-off state.When the FCU 21 is made to be in the thermo-off state or when the FCUperformance varies, the controller 4 controls the opening degree of theheat-medium flow adjusting valve 22 in accordance with the thermo-offstate or the variation of FCU performance.

FIG. 13 is a schematic view indicating the opening degrees of theheat-medium flow adjusting valves 22 in the case where the FCU 21 b ismade to be in the thermo-off state. FIG. 14 is a schematic viewindicating the opening degrees of the heat-medium flow adjusting valves22 in the case where the FCU performance of the FCU 21 c, which is therepresentative FCU, varies.

When the FCU 21 b is made to be in the thermo-off state, it isunnecessary to cause water to flow into the FCU 21 b. Therefore, asindicated in FIG. 13, the valve opening-degree determination unit 42determines the FCU opening degree of the heat-medium flow adjustingvalve 22 associated with the FCU 21 b as 0%, and determines that thebypass opening degree of the heat-medium flow adjusting valve 22 as100%. In this case, the FCU performance of the FCU 21 c, which is therepresentative FCU, does not vary, and only the opening degree of theheat-medium flow adjusting valve 22 associated with the FCU 21 b, whichis made to be in the thermo-off state, is changed.

By contrast, when the FCU performance of the FCU 21 c, which is therepresentative FCU, varies, the performance ratio of the FCU performanceof the FCU 21 a to that of the FCU 21 c and the performance ratio of theFCU performance of the FCU 21 b to that of the FCU 21 c vary. In theexample indicated in FIG. 14, the FCU performance of the FCU 21 c, whichis the representative FCU, varies from 5 to 3 kW, and as a result atthat time, the FCU performance of the FCU 21 a and the FCU performanceof the FCU 21 b are ⅓ of the FCU performance of the FCU 21 c.

Therefore, the valve opening-degree determination unit 42 determines theFCU opening degrees of the heat-medium flow adjusting valves 22associated with the FCU 21 a and the FCU 21 b as 33% (≈100%×⅓), anddetermines the bypass opening degrees of the heat-medium flow adjustingvalves 22 as 67%. As described above, when the FCU performance of theFCU 21 c, which is the representative FCU, varies, the opening degreesof the heat-medium flow adjusting valves 22 associated with the FCU 21 aand the FCU 21 b, which are FCUs other than the representative FCU, arechanged.

In this example, the FCU performance that the FCU is currently requiredto achieved is used as the FCU performance for controlling the openingdegree of the heat-medium flow adjusting valve 22. This, however, is notlimiting. For example, a set FCU performance determined in advance foreach FCU 21 may be used without any change. In this case, it is notnecessary to calculate FCU performance that the FCUs 21 are required tocurrently achieve, and it is therefore possible to simplify theconfiguration related to the control of the opening degrees of theheat-medium flow adjusting valves 22.

As described above, in Embodiment 1, the representative FCU in thesystem is determined, and in accordance with the performance ratiobetween the FCU performance of the representative FCU and the FCUperformance of each of the FCUs 21 other than the representative FCU,the opening degree of the heat-medium flow adjusting valve 22 associatedwith each FCU is determined. Thus, water flows into each FCU 21 at arequired rate, and heat of water can be efficiently used.

In this example, the representative FCU of each system is determinedbased on FCU performance of the FCUs 21. This, however, is not limiting.For example, the representative FCU of each system may be determined inadvance. In the case where the representative FCU is determined inadvance, as described above, the indoor-side bypass pipe 23 of theindoor unit 2 that is associated with the representative FCU can beomitted. Furthermore, in an indoor unit 2 from which the indoor-sidebypass pipe 23 is omitted, the heat-medium flow adjusting valve 22 doesnot need to have a plurality of outflow ports, and has only to have afunction of adjusting the flow rate of water that flows into theheat-medium flow adjusting valve 22 and then causing the water to flowout therefrom.

As described above, in the air-conditioning apparatus 100 according toEmbodiment 1, the indoor units 2 that include respective indoor-sidebypass pipe 23 are connected in series. A heat medium subjected to heatexchange with indoor air is caused to flow into the heat exchangersconnected in series. Thus, since heat of the heat medium is used by theplurality of indoor units 2, the amount of residual heat of the heatmedium can be reduced. In the case where the heat medium is water, aphase change in the heat medium circuit is small, and a change intemperature of the heat medium is smaller than that of refrigerant.Thus, the plurality of indoor units 2 can be connected in series.

Each of the indoor units 2 a to 2 c includes the heat-medium flowadjusting valve 22 that can control the flow rate, the use-side heatexchanger 121 connected with the first outflow port 22 b of theheat-medium flow adjusting valve 22, and the indoor-side bypass pipe 23connected with the second outflow port 22 c of the heat-medium flowadjusting valve 22. Furthermore, in the air-conditioning apparatus 100,the indoor units 2 are connected in series. Thus, since a necessaryamount of water flows into the FCU 21, and heat of water can beefficiently used.

Furthermore, the air-conditioning apparatus 100 includes the controller4 that controls the opening degrees of the heat-medium flow adjustingvalves 22 based on the performance of the respective FCUs 21 of theindoor units 2 a to 2 c. The controller 4 includes the valveopening-degree determination unit 42 that controls the opening degreesof the heat-medium flow adjusting valves 22 based on the performanceratios between the FCU performance of the representative FCU having thehighest CPU performance among the FCU performances of the FCUs 21 of theindoor units 2 and the FCU performance of the other FCUs 21. Thus, it ispossible to supply a necessary amount of water to each of the FCUs 21.

Furthermore, the controller 4 also includes the FCU performancecalculation unit 41 that calculates the FCU performance of each of theplurality of the FCUs 21 based on a temperature at the inlet of each FCU21, a temperature at the outlet thereof, and the temperature of airsucked into the FCU 21. It is therefore possible to calculate the FCUperformance that each of the FCUs 21 is currently required to achieve.

Embodiment 2

Next, an air-conditioning apparatus according to Embodiment 2 of thepresent disclosure will be described. In Embodiment 2, the system #1including the indoor units 2 a to 2 c connected in series and a system#2 including a plurality of indoor units 2 d to 2 f connected in seriesare connected parallel to each other. In this regard, Embodiment 2 isdifferent from Embodiment 1. Regarding Embodiment 2, components that arethe same as those in Embodiment 1 will be denoted by the same referencesigns, and their detailed descriptions will thus be omitted.

[Configuration of Air-Conditioning Apparatus 200]

FIG. 15 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus 200 according to Embodiment 2. Asillustrated in FIG. 15, the air-conditioning apparatus 200 includes theoutdoor unit 1, the plurality of indoor units 2 a to 2 f, and the relayunit 3. The outdoor unit 1 and the relay unit 3 are connected by therefrigerant pipe 10, whereby a refrigerant circuit is formed. The indoorunits 2 a to 2 f and the relay unit 3 are connected by the heat mediumpipe 20, whereby a heat medium circuit is formed. The indoor units 2 ato 2 c are connected in series, thus forming the system #1. The indoorunits 2 d to 2 f are connected in series, thus forming the system #2.The indoor units 2 a to 2 c of the system #1 and the indoor units 2 d to2 f of the system #2 are connected in parallel.

[Operation of Air-Conditioning Apparatus 200]

Next, the operation of the air-conditioning apparatus 200 having theabove configuration will be described. The following description is madewith respect to the flow of water serving as a heat medium thatcirculates in the heat medium circuit. The flow-rate control process inthe indoor unit 2 a to 2 f is the same as that in Embodiment 1, and itsdescription will thus be omitted.

(Flow of Heat Medium)

Referring to FIG. 15, in the air-conditioning apparatus 200, the system#1 including the indoor units 2 a to 2 c connected in series and thesystem #2 including the indoor units 2 d to 2 f connected in series areconnected parallel to the relay unit 3.

In the relay unit 3, water that has flowed out from the intermediateheat exchanger 32 flows out of the relay unit 3 through the heat mediumpipe 20. The water that has flowed out of the relay unit 3 branches offand flows into two systems #1 and #2. The water flows into the indoorunit 2 a, which is the indoor unit located at the most upstream side inthe system #1, and also into the indoor unit 2 d, which is the indoorunit located on the most upstream side in the system #2. The flow ofwater in the system #1 is the same as that of Embodiment 1, and itsdescription will thus be omitted.

In the indoor unit 2 d of the system #2, the water that has flowed intothe indoor unit 2 d flows through the FCU 21 d or an indoor-side bypasspipe 23 of the indoor unit 2 d at a flow rate that depends on the setopening degree of the heat-medium flow adjusting valve 22. The waterthat has flowed into the FCU 21 d exchanges heat with indoor air toreceive or transfer heat, thereby cooling or heating the indoor air, andthe water then flows out of the FCU 21 d. The water that has flowed outof the FCU 21 d and the water that flows through the indoor-side bypasspipe 23 joins each other at a location downstream of the FCU 21 d, andflows into the indoor unit 2 e, which is an indoor unit locateddownstream of the indoor unit 2 d.

In the indoor unit 23 e, the water that has flowed into the indoor unit2 e flows through an FCU 21 e or an indoor-side bypass pipe 23 of theindoor unit 2 e at a flow rate that depends on the set opening degree ofthe heat-medium flow adjusting valve 22. The water that has flowed intothe FCU 21 e exchanges heat with indoor air to receiver or transfer heatfrom or to the indoor air, thereby cooling or heating the indoor air,and the water then flows out of the FCU 21 e. The water that has flowedout of the FCU 21 e and the water that flows through the indoor-sidebypass pipe 23 join each other at a location downstream of the FCU 21 e,and flows into the indoor unit 2 f, which is an indoor unit locateddownstream of the indoor unit 2 e.

In the indoor unit 2 f, the water that has flowed into the indoor unit 2f flows through an FCU 21 f or an indoor-side bypass pipe 23 of theindoor unit 2 f at a flow rate that depends on the set opening degree ofthe heat-medium flow adjusting valve 22. The water that has flowed intothe FCU 21 f exchanges heat with indoor air to receive or transfer heatfrom or to the indoor air, thereby cooling or heating the indoor air,and the water flows out of the FCU 21 f. The water that has flowed outof the FCU 21 f and the water that flows through the indoor-side bypasspipe 23 join each other at a location downstream of the FCU 21 f, andflows out of the indoor unit 2 f.

The water that has flowed out of the indoor unit 2 c, which is theindoor unit located on the most downstream side in the system #1, andthe water that has flowed out of the indoor unit 2 f, which is theindoor unit located on the most downstream side in the system #2, joineach other, and flow into the relay unit 3 through the heat medium pipe20. The water that has flowed into the relay unit 3 flows into theintermediate heat exchanger 32 via the pump 33. Thereafter, the abovecirculation is repeated.

As described above, the air-conditioning apparatus 200 according toEmbodiment 2 includes the plurality of systems each of which includesthe plurality of indoor units 2 connected in series, and the pluralityof systems are connected in parallel. Even in the case where theplurality of systems, each of which includes the plurality of indoorunits 2 connected in series, are provided in the above manner, anecessary amount of water flows into each of the FCUs 21, and heat ofwater can be efficiently used, as in Embodiment 1.

Embodiment 3

Next, an air-conditioning apparatus according to Embodiment 3 of thepresent disclosure will be described. In Embodiment 3, the system #1including the indoor units 2 a to 2 c connected in series, the system #2including the plurality of indoor units 2 d to 2 f connected in series,and a system #3 including a plurality of indoor units 2 g to 2 iconnected in series are connected in parallel. In this regard,Embodiment 3 is different from Embodiments 1 and 2. Regarding Embodiment3, components that are the same as those in any of Embodiments 1 and 2will be denoted by the same reference signs, and their detaileddescriptions will thus be omitted.

[Configuration of Air-Conditioning Apparatus 300]

FIG. 16 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus 300 according to Embodiment 3. Asillustrated in FIG. 16, the air-conditioning apparatus 300 includes theoutdoor unit 1, the plurality of indoor units 2 a to 2 i, and the relayunit 3. The outdoor unit 1 and the relay unit 3 are connected by therefrigerant pipe 10, whereby a refrigerant circuit is formed. Theplurality of indoor units 2 a to 2 i and the relay unit 3 are connectedby the heat medium pipe 20, whereby a heat medium circuit is formed.Furthermore, the indoor units 2 a to 2 c are connected in series, thusforming the system #1. The indoor units 2 d to 2 f are connected inseries, thus forming the system #2. The indoor units 2 g to 2 i areconnected in series, thus forming the system #3. The indoor units 2 a to2 c of the system #1, the indoor units 2 d to 2 f of the system #2, andthe indoor units 2 g to 2 i of the system #3 are connected in parallel.

[Operation of Air-Conditioning Apparatus 300]

Next, the operation of the air-conditioning apparatus 300 having theabove configuration will be described. The following description is madewith respect to the flow of water serving as a heat medium thatcirculates through the heat medium circuit and the control of the flowrate of water for each of the systems #1 to #3.

(Flow of Heat Medium)

Referring to FIG. 16, in the air-conditioning apparatus 300, the system#1 including the indoor units 2 a to 2 c connected in series, the system#2 including the indoor units 2 d to 2 f connected in series, the system#3 including the indoor units 2 g to 2 i connected in series areconnected parallel to the relay unit 3.

In the relay unit 3, water that has flowed out of the intermediate heatexchanger 32 flows out of the relay unit 3 through the heat medium pipe20. The water that has flowed out of the relay unit 3 branches off andflows into three systems #1 to #3. The water flows into the indoor unit2 a, which is the indoor unit located on the most upstream side in thesystem #1, into the indoor unit 2 d, which is the indoor unit located onthe most upstream side in the system #2, and into the indoor unit 2 g,which is the indoor unit located on the most upstream side in the system#3. The flow of water in the systems #1 and #2 is the same as that inEmbodiment 2, and its description will thus be omitted.

In the indoor unit 2 g of the system #3, the water that has flowed intothe indoor unit 2 g flows through an FCU 21 g or an indoor-side bypasspipe 23 of the indoor unit 2 g at a flow rate that depends on the setopening degree of the heat-medium flow adjusting valve 22. The waterthat has flowed into the FCU 21 g exchanges heat with indoor air toreceive or transfer heat from or to the indoor air, thereby cooling orheating the indoor air, and the water flows out of the FCU 21 g. Thewater that has flowed out of the FCU 21 g and the water that flowsthrough the indoor-side bypass pipe 23 join each other at a locationdownstream of the FCU 21 g, and flow into the indoor unit 2 h, which isthe indoor unit located downstream of the indoor unit 2 g.

In the indoor unit 2, the water that has flowed into the indoor unit 2 hflows through an FCU 21 h or an indoor-side bypass pipe 23 of the indoorunit 2 h at a flow rate that depends on the set opening degree of theheat-medium flow adjusting valve 22. The water that has flowed into theFCU 21 h exchanges heat with indoor air to receive or transfer heat fromor to the indoor air, thereby cooling or heating the indoor air, and thewater flows out of the FCU 21 h. The water that has flowed out of theFCU 21 h and the water that flows through the indoor-side bypass pipe 23join each other at a location downstream of the FCU 21 h, and flow intothe indoor unit 2 i, which is the indoor unit located downstream of theindoor unit 2 h.

In the indoor unit 2 i, the water that has flowed into the indoor unit 2i flows through an FCU 21 i or an indoor-side bypass pipe 23 of the FCU21 i at a flow rate that depends on the set opening degree of theheat-medium flow adjusting valve 22. The water that has flowed into theFCU 21 i exchanges heat with indoor air to receive or transfer heat fromor to the indoor air, thereby cooling or heating the indoor air, and thewater flows out of the FCU 21 i. The water that has flowed out of theFCU 21 i and the water that flows through the indoor-side bypass pipe 23join each other at a location downstream of the FCU 21 i, and flow outof the indoor unit 2 i.

The water that has flowed out of the indoor unit 2 c, which is theindoor unit located on the most downstream side in the system #1, thewater that has flowed out of the indoor unit 2 f, which is the indoorunit located on the most downstream side in the system #2, and the waterthat has flowed out of the indoor unit 2 i, which is the indoor unitlocated on the most downstream side in the system #3, join together, andflow into the relay unit 3 through the heat medium pipe 20. The waterthat has flowed into the relay unit 3 flows into the intermediate heatexchanger 32 via the pump 33. Thereafter, the above circulation isrepeated.

(Control of Flow Rates of Water for Systems #1 to #3)

Next, the control of the flow rates of water for the systems #1 to #3will be described. The following is made with respect to the control ofthe flow rates of water in the case where the representative FCUs in thesystems #1 to #3 have different FCU performance. FIGS. 17 to 20 areschematic views indicating the opening degrees of the heat-medium flowadjusting valves 22 in the case where the representative FCUs in therespective systems #1 to #3 have different FCU performance. In FIGS. 17to 20, the FCUs 21 indicated by bold lines are the representative FCUsin the systems #1 to #3.

FIG. 17 is a schematic view indicating a first example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs in the systems #1 to #3 have different FCUperformance. The first example indicated in FIG. 17 is an example inwhich the FCU opening degree of the heat-medium flow adjusting valve 22that depends on the representative FCU in each of all systems #1 to #3is set to 100% regardless of the FCU performance of the representativeFCU.

In the first example, the representative FCUs of the systems #1 to #3are the FCUs 21 c, 21 e and 21 g, respectively. Therefore, theheat-medium flow adjusting valves 22 associated with the FCUs 21 c, 21 eand 21 g are set as illustrated in FIG. 5. In this case, water flowsequally in the systems #1 to #3, and the FCU opening degree of theheat-medium flow adjusting valve 22 that depends on the representativeFCU of each of the systems #1 to #3 is 100%. It is therefore possible tosimplify the control of the heat-medium flow adjusting valves 22associated with the representative FCUs.

In this example, the representative FCU of the system #2 has the highestFCU performance, and in the systems #1 and #3, water flows at a flowrate equivalent to that in the system #2. Therefore, the performance ofeach of the systems #1 and #3 is excessively high, and thus an indoorspace may be excessively cooled or heated. Thus, in this case, it isappropriate that the FCU in each of the systems #1 and #3 is made to bein the thermos-off state, to thereby prevent excessive cooling orexcessive heating.

To be more specific, the valve opening-degree determination unit 42 setsthe bypass opening degree of the heat-medium flow adjusting valve 22associated with the FCU 21 a in the system #1 to 100%, and causes theFCU 21 a to be in the thermo-off state. Furthermore, the valveopening-degree determination unit 42 sets the bypass opening degree ofthe heat-medium flow adjusting valve 22 associated with the FCU 21 i inthe system #3 to 100%, and causes the FCU 21 i to be in the thermo-offstate.

FIG. 18 is a schematic view illustrating a second example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs of systems #1 to #3 have difference FCU performance.The second example indicated in FIG. 18 is an example in which in orderto reduce excessively high performance in the first example, expansiondevices for controlling the flow rate are provided at respectivepositions immediately after the heat medium pipes in the respectivesystems #1 to #3 branch off, that is, on the most upstream sides of therespective systems #1 to #3. Thus, a necessary amount of water for eachof the systems #1 to #3 is supplied to each system.

In the second example, the FCU performance of the FCU 21 e, which is therepresentative FCU of the system #2, is 7 kW, and the FCU 21 e has thehighest FCU performance. Thus, the controller 4 sets the opening degreeof the expansion device of the system #2 such that the expansion deviceof the system #2 is made to be in a fully opened state, and determinesthe opening degrees of the expansion devices of the systems #1 and #3based on the FCU performance of the representative FCU of the system #2.In this case, the FCU performance of the FCU 21 c, which is therepresentative FCU of the system #1, is 5 kW, and the opening degree ofthe expansion device of the system #1 is thus determined as 71% (≈5 kW/7kW×100%). The FCU performance of the FCU 21 g, which is therepresentative FCU of the system #3, is 4 kW and the opening degree ofthe expansion device of the system #3 is thus determined as 57% (≈4 kW/7kW×100%).

In the case where a FCU 21 to be caused to be in the thermo-off state ispresent in a system, the heat-medium flow adjusting valve 22 associatedwith the FCU 21 may be set as illustrated in FIG. 8. That is, the FCUopening degree of the heat-medium flow adjusting valve 22 is set to 0%,and the bypass opening degree is set to the set opening degree. When theopening degree of the heat-medium flow adjusting valve 22 is set asillustrated in FIG. 8, the heat-medium flow adjusting valve 22 serves asan expansion device, whereby the flow rate of water that flows into theFCUs 21 following the above associated FCU 21 is controlled. Therefore,the flow rate of water that flows through each of the systems #1 to #3can be controlled without providing the expansion devices describedabove.

FIG. 19 is a schematic view illustrating a third example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs in the respective systems #1 to #3 have differenceFCU performance. The third example indicated in FIG. 19 is an example inwhich the heat-medium flow adjusting valves 22 associated with therepresentative FCUs in the systems #1 to #3 are made to have differentFCU opening degrees in accordance with the FCU performance of therepresentative FCUs.

In the third example, the FCU opening degree of the heat-medium flowadjusting valve 22 associated with the representative FCU having thehighest FCU performance among the FCU performances of the representativeFCUs in the respective systems #1 to #3 is determined as 100%. The FCUopening degrees of the heat-medium flow adjusting valves 22 associatedwith the representative FCUs other than the above representative FCU aredetermined based on respective performance ratios.

More specifically, the FCU performance of the FCU 21 e, which is therepresentative FCU of the system #2, is 7 kW and the highest in theFCUs. Thus, the controller 4 sets the FCU opening degree of theheat-medium flow adjusting valve 22 associated with the representativeFCU of the system #2 to 100%. Then, the controller 4 determines the FCUopening degrees of the heat-medium flow adjusting valves 22 associatedwith the representative FCUs of the systems #1 and #3 based on therespective ratios of the FCU performance of the representative FCUs tothe above set FCU opening degree of the heat-medium flow adjusting valve22.

In this case, the FCU performance of the FCU 21 c, which is therepresentative FCU of the system #1, is 5 kW. Therefore, based on theperformance ratio between the FCU performance of the FCU 21 c and theFCU performance of the representative FCU in the system #2, it isdetermined that the FCU opening degree of the heat-medium flow adjustingvalve 22 associated with the representative FCU of the system #1 is 71%(≈5 kW/7 kW×100%). The FCU performance of the FCU 21 g, which is therepresentative FCU of the system #3, is 4 kW. Therefore, based on theperformance ratio between the FCU performance of the FCU 21 g and theFCU performance of the representative FCU in the system #2, it isdetermined that the FCU opening degree of the heat-medium flow adjustingvalve 22 associated with the representative FCU of the system #3 is 57%(≈4 kW/7 kW×100%).

As described above, by setting the opening degrees of the heat-mediumflow adjusting valves 22 to different values based on the respective FCUperformance of the representative FCUs of the respective systems #1 to#3, it is possible to perform a fine control such that air conditioningperformance is controlled for respective air-conditioned spaces wherethe indoor units 2 of the systems #1 to #3 are provided. Furthermore, itis possible to reduce the flow rate of water into the FCU 21 at a flowrate higher than a required flow rate, and heat can be more efficientlyused.

In the third example, the FCUs 21 can achieve required FCU performance,and the flow rates at which water flows through the respective systems#1 to #3 are equivalent to each other. Thus, water flows into each ofthe systems #1 and #3 at an excessively high flow rate.

FIG. 20 is a schematic view illustrating a fourth example of the openingdegrees of the heat-medium flow adjusting valves in the case where therepresentative FCUs in the respective systems #1 to #3 have differenceFCU performance. The fourth example indicated in FIG. 20 is an examplewhere the opening degrees of the heat-medium flow adjusting valves 22associated with the representative FCUs of the systems other than thesystem including the representative FCU having the highest performanceare adjusted in order to reduce the flow rate of water that flows at anexcessively high flow rate in the third example.

In the fourth example, as in the third example, the valve opening-degreedetermination unit 42 sets the FCU opening degree of the heat-mediumflow adjusting valve 22 associated with the FCU 21 e, which is therepresentative FCU of the system #2, to 100%. Furthermore, the valveopening-degree determination unit 42 sets the opening degrees of theheat-medium flow adjusting valves 22 associated with the FCU 21 c andthe FCU 21 g, which are the representative FCUs of the systems #1 and #3that are systems other than the system #2, as illustrated in FIG. 10.The opening degrees of the heat-medium flow adjusting valves 22 are setas illustrated in FIG. 10, whereby the flow rate of water that flowsinto the FCUs 21 following the above associated FCU 21 is adjusted.

That is, the FCU opening degrees of the heat-medium flow adjustingvalves 22 associated with the representative FCUs of the systems #1 and#3 are set based on the ratio of the FCU performance of therepresentative FCU to the FCU opening degree of the heat-medium flowadjusting valve 22 associated with the representative FCU of the system#2. Furthermore, at this time, the bypass opening degrees of theheat-medium flow adjusting valves 22 are set to 0%.

More specifically, the heat-medium flow adjusting valve 22 associatedwith the FCU 21 c, which is the representative FCU of the system #1, isset such that the FCU opening degree is 71% and the bypass openingdegree is 0%. Furthermore, the heat-medium flow adjusting valve 22associated with the FCU 21 g, which is the representative FCU of thesystem #3, is set such that the FCU opening degree is 57% and the bypassopening degree is 0%.

As described above, the opening degrees of the heat-medium flowadjusting valves 22 are set such that the bypass opening degrees of theheat-medium flow adjusting valves 22 associated with the representativeFCUs of the systems other than the system including the representativeFCU having the highest performance are 0%, whereby the flow rates ofwater for the respective systems #1 to #3 can be adjusted.

As described above, in the air-conditioning apparatus 300 according toEmbodiment 3, the valve opening-degree determination unit 42 sets theopening degrees of the heat-medium flow adjusting valves 22 associatedwith the representative FCUs of the respective systems such that theheat-medium flow adjusting valves 22 are made to be in the fully openedstate. Furthermore, the valve opening-degree determination unit 42determines the opening degrees of the heat-medium flow adjusting valves22 associated with other FCUs based on the respective performanceratios. Therefore, it is possible to simplify the control of the openingdegrees of the heat-medium flow adjusting valves 22 in the respectivesystems.

Moreover, the expansion devices are provided on the most upstream sidesof the respective systems, and the controller 4 determines the openingdegrees of the expansion devices of the respective systems based on theperformance ratios of the representative FCUs of the respective systems.Therefore, it is possible to supply a required amount of water to eachof the systems.

The valve opening-degree determination unit 42 sets the opening degreeof the heat-medium flow adjusting valve 22 connected to therepresentative FCU having the highest FCU performance among therepresentative FCUs of all the systems such that the heat-medium flowadjusting valve 22 is made to be in the fully opened state. Furthermore,the valve opening-degree determination unit 42 determines the openingdegree of the heat-medium flow adjusting valve 22 connected to anotherrepresentative FCU based on the performance ratio of the FCU performanceof the above other representative FCU to the FCU performance of therepresentative FCU having the highest performance. Then, the valveopening-degree determination unit 42 determines the opening degree ofthe heat-medium flow adjusting valve 22 associated with the above otherrepresentative FCU such that the heat-medium flow adjusting valve 22allows the heat-medium outflow side of the other representative FCU tocommunicate with the second outflow port 22 c. As a result, the flowrate of water for each system is appropriately set, and unnecessarytransfer power can be reduced.

Embodiment 4

Next, an air-conditioning apparatus according to Embodiment 4 of thepresent disclosure will be described. In Embodiment 4, the indoor units2 a to 2 i are provided with respective indoor-side controllers. In thisregard, Embodiment 4 is different from Embodiments 1 to 3. RegardingEmbodiment 4, components that are the same as those of any ofEmbodiments 1 to 3 will be denoted by the same reference signs, andtheir detailed descriptions will thus be omitted.

[Configuration of Air-Conditioning Apparatus 400]

FIG. 21 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus 400 according to Embodiment 4. Asillustrated in FIG. 21, the air-conditioning apparatus 400 includes theoutdoor unit 1, the plurality of indoor units 2 a to 2 i, and the relayunit 3. The outdoor unit 1 and the relay unit 3 are connected by therefrigerant pipe 10, whereby a refrigerant circuit is formed. Theplurality of indoor units 2 a to 2 i and the relay unit 3 are connectedby the heat medium pipe 20, whereby a heat medium circuit is formed. Theindoor units 2 a to 2 c are connected in series, thus forming the system#1. The indoor units 2 d to 2 f are connected in series, thus formingthe system #2. The indoor units 2 g to 2 i are connected in series, thusforming the system #3. The indoor units 2 a to 2 c of the system #1, theindoor units 2 d to 2 f of the system #2, and the indoor units 2 g to 2i of the system #3 are connected in parallel, respectively.

In Embodiment 4, as illustrated in FIG. 21, each of the indoor units 2 ato 2 i includes an indoor-side controller 27 in addition to theconfiguration as illustrated in FIG. 2. The indoor-side controller 27controls components in an indoor unit 2 in which the indoor-sidecontroller 27 is provided. Of various controls by the controller 4 ofeach of Embodiment 1 to 3, a control related to the indoor unit 2 inwhich the indoor-side controller 27 is provided is performed by theindoor-side controller 27. To be more specific, the indoor-sidecontroller 27 controls calculation of the FCU performance of the FCU 21,the opening degree of the heat-medium flow adjusting valve 22 based onthe calculated FCU performance, etc.

The indoor-side controller 27 communicates with indoor-side controllers27 provided in the other indoor units 2 and with the controller 4provided in the relay unit 3. For example, the indoor-side controllers27 exchanges information with each other, which is, for example,information from sensors including the inlet temperature sensor 24, theoutlet temperature sensor 25, the suction temperature sensor 26 andother sensors, and information related to the control of the openingdegree of the heat-medium flow adjusting valve 22.

As described above, the indoor units 2 a to 2 i are provided with therespective indoor-side controllers 27, whereby it is possible to performan interlocking control between the outdoor unit 1, the indoor units 2and the relay unit 3. Furthermore, it is possible to easily replace eachindoor unit 2 solely with a new one.

Embodiment 5

Next, an air-conditioning apparatus according to Embodiment 5 of thepresent disclosure will be described. In Embodiment 5, a cooling deviceand a heating device are provided in the air-conditioning apparatus. Inthis regard, Embodiment 4 is different from Embodiments 1 to 4.Regarding Embodiment 5, components that are the same as those in any ofEmbodiments 1 to 4 will be denoted by the same reference signs, andtheir detailed descriptions will thus be omitted.

[Configuration of Air-Conditioning Apparatus 500]

FIG. 22 is a schematic view illustrating an example of the configurationof an air-conditioning apparatus 500 according to Embodiment 5. Asillustrated in FIG. 22, the air-conditioning apparatus 500 includes theoutdoor unit 1, the indoor units 2 a to 2 c, the relay unit 3, a coolingdevice 5, and a heating device 6. The following description is made byreferring to by way of example the case where the indoor units 2 formthe system #1 only. This, however, is not limiting. The indoor units 2may form a plurality of systems. Alternatively, the indoor units 2 maynot be provided.

The outdoor unit 1 and the relay unit 3 are connected by the refrigerantpipe 10, whereby a refrigerant circuit is formed. The indoor units 2 ato 2 c, the cooling device 5, the heating device 6, and the relay unit 3are connected by the heat medium pipe 20, whereby a heat medium circuitis formed. The indoor units 2 a to 2 c are connected in series, thusforming the system #1. The cooling device 5 and the heating device 6 areconnected in series, thus forming a system #4. The indoor units 2 a to 2c of the system #1 and the cooling device 5 and the heating device 6 ofthe system #4 are connected in parallel.

(Cooling Device 5)

The cooling device 5 is a device that generates cooling energy. Forexample, the cooling device 5 is provided in a room where heat isgenerated at all time, such as a refrigerator room, a freezer room, or acomputer room. The cooling device 5 is provided to cool the inside ofthe room. The cooling device 5 includes a cooling-side intermediate heatexchanger 51, a cooling-side heat-medium flow adjusting valve 52, acompressor 53, an expansion valve 54, and a use-side heat exchanger 55.

The cooling-side intermediate heat exchanger 51 causes heat exchange tobe performed between a heat medium that flows in the heat medium circuitconnected with a heat-medium-side flow passage and cooling refrigerantthat flows in the cooling refrigerant circuit connected with arefrigerant-side flow passage. The cooling-side intermediate heatexchanger 51 operates as a condenser that transfers heat of the coolingrefrigerant to the heat medium to condense the cooling refrigerant.

The cooling-side heat-medium flow adjusting valve 52 is an electricthree-way valve having an inflow port 52 a, a first outflow port 52 b,and a second outflow port 52 c, and is provided on a water inflow sideof the cooling-side intermediate heat exchanger 51. The cooling-sideheat-medium flow adjusting valve 52 is provided to cause water thatflows thereinto to branch off. In the cooling-side heat-medium flowadjusting valve 52, the first outflow port 52 b is connected to thewater inflow side of the cooling-side intermediate heat exchanger 51,and the second outflow port 52 c is connected to the water outflow sideof the cooling-side intermediate heat exchanger 51 by a cooling-sidebypass pipe 50. Thus, the second outflow port 52 c of the cooling-sideheat-medium flow adjusting valve 52 and the water outflow side of thecooling-side intermediate heat exchanger 51 are connected.

The cooling-side heat-medium flow adjusting valve 52 has a configurationsimilar to that of the heat-medium flow adjusting valve 22. To be morespecific, the opening degree of the cooling-side heat-medium flowadjusting valve 52 is controlled in opening degree by the controller 4to allow water that has flowed into the inflow port 52 a to flow outfrom both the first outflow port 52 b and the second outflow port 52 cat an adjusted flow rate.

In this example, the cooling-side bypass pipe 50 is provided in thecooling device 5. This, however, is not limiting. The cooling-sidebypass pipe 50 may be provided outside the cooling device 5 andconnected to the cooling device 5 by, for example, a connection fitting.Thus, the length of the cooling-side bypass pipe 50 is shortened, and itis therefore possible to reduce a loss caused by radiation of heat atthe time when water flows through the pipe.

The compressor 53 sucks low-temperature, low-pressure coolingrefrigerant, compresses the sucked refrigerant into high-temperature,high-pressure cooling refrigerant, and discharges the high-temperature,high-pressure refrigerant. The compressor 53 is, for example, aninverter compressor. The operating frequency of the compressor 53 iscontrolled by the controller 4.

The expansion valve 54 causes the cooling refrigerant to expand. Theexpansion valve 54 is a valve whose opening degree can be controlled by,for example, an electronic expansion valve. The opening degree of theexpansion valve 54 is controlled by a controller of the cooling device 5(not illustrated). The use-side heat exchanger 55 causes heat exchangeto be performed between the cooling refrigerant and indoor air suppliedby a fan (not illustrated). As a result, cooling air is generated asconditioned air to be supplied into an indoor space.

The cooling device 5 includes an inlet temperature sensor 56, an outlettemperature sensor 57, and a suction temperature sensor 58. The inlettemperature sensor 56 is provided on the water inflow side of thecooling-side intermediate heat exchanger 51 to detect the temperature ofwater that flows into the cooling-side intermediate heat exchanger 51.Also, the inlet temperature sensor 56 detects an inlet temperature ofwater in the system #4. The outlet temperature sensor 57 is provided onthe water outflow side of the cooling-side intermediate heat exchanger51 to detect the temperature of water that flows out of the cooling-sideintermediate heat exchanger 51. The suction temperature sensor 58 isprovided on an air suction side of the cooling-side intermediate heatexchanger 51 to detect the temperature of air that is sucked into thecooling-side intermediate heat exchanger 51.

(Heating Device 6)

The heating device 6 generates heating energy. For example, the heatingdevice 6 is provided in a room that uses a radiant heating such as floorheating, or in a greenhouse for use in cultivation of a tropical plant,etc., or in a room where hot water is used, such as a kitchenette. Theheating device 6 is provided to generate and store hot water. Theheating device 6 includes a heating-side intermediate heat exchanger 61,a heating-side heat-medium flow adjusting valve 62, a compressor 63, anexpansion valve 64, a water heat exchanger 65, a hot water storage tank71, and a water supply pump 72.

The heating-side intermediate heat exchanger 61 causes heat exchange tobe performed between a heat medium that flows in the heat medium circuitconnected with the heat-medium-side flow passage and heating refrigerantthat flows in the heating refrigerant circuit connected with therefrigerant-side flow passage. The heating-side intermediate heatexchanger 61 operates as an evaporator that evaporates the heatingrefrigerant to cool the heat medium by heat of vaporization that isproduced when the heating refrigerant is evaporated.

The heating-side heat-medium flow adjusting valve 62 is an electricthree-way valve having an inflow port 62 a, a first outflow port 62 b,and a second outflow port 62 c, and is provided on the water inflow sideof the heating-side intermediate heat exchanger 61. The heating-sideheat-medium flow adjusting valve 62 is provided to cause water thatflows thereinto to branch off. The first outflow port 62 b of theheating-side heat-medium flow adjusting valve 62 is connected to thewater inflow side of the heating-side intermediate heat exchanger 61.The second outflow port 62 c is connected to the water outflow side ofthe heating-side intermediate heat exchanger 61 by a heating-side bypasspipe 60. Thus, the second outflow port 62 c of the heating-sideheat-medium flow adjusting valve 62 and the water outflow side of theheating-side intermediate heat exchanger 61 are connected.

The heating-side heat-medium flow adjusting valve 62 has a configurationsimilar to that of the heat-medium flow adjusting valve 22 and thecooling-side heat-medium flow adjusting valve 52. To be more specific,the heating-side heat-medium flow adjusting valve 62 is controlled inopening degree by the controller 4 to allow water that has flowed intothe inflow port 62 a to flow out from both the first outflow port 62 band the second outflow port 62 c at an adjusted flow rate.

In this example, the heating-side bypass pipe 60 is provided in theheating device 6. This, however, is not limiting. The heating-sidebypass pipe 60 may be provided outside the heating device 6 andconnected to the heating device 6 by, for example, a connection fitting.Thus, the length of the heating-side bypass pipe 60 is shortened, and itis therefore possible to reduce a loss caused by, for example, radiationof heat at the time when water flows through the pipe.

The compressor 63 sucks low-temperature, low-pressure heatingrefrigerant, compresses the sucked refrigerant into high-temperature,high-pressure heating refrigerant, and discharges the high-temperature,high-pressure refrigerant. The compressor 63 is, for example, aninverter compressor. The operating frequency of the compressor 63 iscontrolled by the controller 4.

The expansion valve 64 causes the heating refrigerant to expand. Theexpansion valve 64 is a valve whose opening degree can be controlled by,for example, an electronic expansion valve. The opening degree of theexpansion valve 64 is controlled by a controller of the heating device 6(not illustrated). The water heat exchanger 65 causes heat exchange tobe performed between heating refrigerant and a heat medium, for example,water that is stored in the hot water storage tank 71.

The hot water storage tank 71 stores water supplied from the outside.The hot water storage tank 71 has a water supply port and an outflowport that are located in a lower portion of the hot water storage tank71, and also has an inflow port that is located in an upper portion ofthe hot water storage tank 71. Water is supplied to the hot waterstorage tank 71 from the outside through the water supply port, and thehot water storage tank 71 stores supplied unheated water. The unheatedwater stored in the hot water storage tank 71 flows out through theoutflow port, and is supplied to the water heat exchanger 65.

The hot water storage tank 71 is supplied with water heated at the waterheat exchanger 65 through the inflow port, and stores the suppliedheated water. The heated water stored in the hot water storage tank 71is discharged to the outside, and used as hot water for, for example, ashower.

The water supply pump 72 is driven by a motor (not illustrated), andsupplies water that has flowed out of the hot water storage tank 71 tothe water heat exchanger 65. The driving of the water supply pump 72 iscontrolled by a controller of the heating device 6 (not illustrated).

The heating device 6 includes an inlet temperature sensor 66, an outlettemperature sensor 67, and a heat medium temperature sensor 68. Theinlet temperature sensor 66 is provided on the water inflow side of theheating-side intermediate heat exchanger 61 to detect the temperature ofwater that flows into the heating-side intermediate heat exchanger 61.The outlet temperature sensor 67 is provided on the water outflow sideof the heating-side intermediate heat exchanger 61 to detect thetemperature of water that flows out of the heating-side intermediateheat exchanger 61. Also, the outlet temperature sensor 67 detects anoutlet temperature of water in the system #4. The heat mediumtemperature sensor 68 is provided close to the heating-side intermediateheat exchanger 61 to detect the temperature of the heat medium at aposition close to the heating-side intermediate heat exchanger 61.

[Operation of Air-Conditioning Apparatus 500]

Next, the operation of the air-conditioning apparatus 500 having theabove configuration will be described. The following description is madewith respect to the flow of water that is a heat medium that circulatesin the heat medium circuit. Referring to FIG. 22, in theair-conditioning apparatus 200, the system #1 includes the indoor units2 a to 2 c connected in series, and the system #4 includes the coolingdevice 5 and the heating device 6 that are connected in series; and thesystem #1 and the system #4 are connected parallel to the relay unit 3.

In the relay unit 3, water that has flowed out of the intermediate heatexchanger 32 flows out of the relay unit 3 through the heat medium pipe20. The water that has flowed out of the relay unit 3 branches off andflows into two systems #1 and #4, and then flows into the indoor unit 2a, which is located on the most upstream side in the system #1, and intothe cooling device 5 in the system #4. The flow of water in the system#1 is the same as that in Embodiment 1, and its description will thus beomitted.

The water that has flowed into the cooling device 5 in the system #4flows through the cooling-side intermediate heat exchanger 51 or thecooling-side bypass pipe 50 at a flow rate that depends on the setopening degree of the cooling-side heat-medium flow adjusting valve 52.The water that has flowed into the cooling-side intermediate heatexchanger 51 exchanges heat with the cooling refrigerant to cool therefrigerant, and flows out of the cooling-side intermediate heatexchanger 51. The water that has flowed out of the cooling-sideintermediate heat exchanger 51 and the water that flows through thecooling-side bypass pipe 50 join each other at a location downstream ofthe cooling-side intermediate heat exchanger 51, and flow into theheating device 6, which is located downstream of the cooling device 5.

The water that has flowed into the heating device 6 flows through theheating-side intermediate heat exchanger 61 or the heating-side bypasspipe 60 at a flow rate that depends on the set opening degree of theheating-side heat-medium flow adjusting valve 62. The water that hasflowed into the heating-side intermediate heat exchanger 61 exchangesheat with the heating refrigerant to heat the refrigerant, and flows outof the heating-side intermediate heat exchanger 61. The water that hasflowed out of the heating-side intermediate heat exchanger 61 and thewater that flows through the heating-side bypass pipe 60 join each otherat a location downstream of the heating-side intermediate heat exchanger61, and flow out of the heating device 6.

The water that has flowed out of the indoor unit 2 c, which is locatedon the most downstream side in the system #1 and the water that hasflowed out of the heating device 6 in the system #4 join each other, andthen flow into the relay unit 3 through the heat medium pipe 20. Thewater that has flowed into the relay unit 3 flows into the intermediateheat exchanger 32 via the pump 33. Thereafter, the above circulation isrepeated.

On the other hand, in the cooling device 5, the cooling refrigerant thatflows through the cooling refrigerant circuit is compressed bycompressor 53 and then discharged from the compressor 53. The coolingrefrigerant discharged from the compressor 53 flows into thecooling-side intermediate heat exchanger 51. The cooling refrigerantthat has flowed into the cooling-side intermediate heat exchanger 51exchanges heat with water that flows through the heat medium circuit,and is condensed while transferring heat to the water to heat the water.Then, the cooling refrigerant flows out of the cooling-side intermediateheat exchanger 51

The cooling refrigerant that has flowed out of the cooling-sideintermediate heat exchanger 51 is reduced in pressure and expanded bythe expansion valve 54, and flows out of the expansion valve 54. Thecooling refrigerant that has flowed out of the expansion valve 54 flowsinto the use-side heat exchanger 55. The cooling refrigerant that hasflowed into the use-side heat exchanger 55 exchanges heat with indoorair to receive heat from the indoor air and evaporate, and then flowsout of the use-side heat exchanger 55. The cooling refrigerant that hasflowed out of the use-side heat exchanger 55 is sucked into thecompressor 53. Thereafter, the cooling refrigerant repeats the abovecirculation.

In the heating device 6, the heating refrigerant that flows through theheating refrigerant circuit is compressed by the compressor 63 anddischarged from the compressor 63. The heating refrigerant dischargedfrom the compressor 63 flows into the water heat exchanger 65. Theheating refrigerant that has flowed into the water heat exchanger 65exchanges heat with unheated water that has flowed out of the hot waterstorage tank 71, and is condensed while transferring heat to theunheated water to heat the water. Then, the heating refrigerant flowsout of the water heat exchanger 65.

The heating refrigerant that has flowed out of the water heat exchanger65 is reduced in pressure and expanded by the expansion valve 64, andthen flows out of the expansion valve 64. The heating refrigerant thathas flowed out of the expansion valve 64 flows into the heating-sideintermediate heat exchanger 61. The heating refrigerant that has flowedinto the heating-side intermediate heat exchanger 61 exchanges heat withwater that flows through the heat medium circuit to receive heat fromthe water and evaporate, and then flows out of the heating-sideintermediate heat exchanger 61. The heating refrigerant that has flowedout of the heating-side intermediate heat exchanger 61 is sucked intothe compressor 63. Thereafter, the heating refrigerant repeats the abovecirculation.

Furthermore, when the water supply pump 72 is driven, unheated waterflows out from the outflow port provided in the lower portion of the hotwater storage tank 71. The unheated water that has flowed out of the hotwater storage tank 71 flows into the water heat exchanger 65. Theunheated water that has flowed into the water heat exchanger 65exchanges heat with the heating refrigerant and is thus heated. Then,the heated water flows out of the water heat exchanger 65. The heatedwater that has flowed out of the water heat exchanger 65 flows into thehot water storage tank 71 from the inflow port provided in the upperportion of the hot water storage tank 71, and is stored in the hot waterstorage tank 71. Thereafter, the unheated water in the hot water storagetank 71 repeats the above circulation.

It should be noted that in the system #4, in the case where one of thecooling device 5 and the heating device 6 is in the stopped state, thecontroller 4 controls the opening degree of one of the cooling-sideheat-medium flow adjusting valve 52 and the heating-side heat-mediumflow adjusting valve 62 that is associated with the above one of thecooling device 5 and the heating device 6 that is in the stopped state.Under such a control, the cooling-side intermediate heat exchanger 51 orthe heating-side intermediate heat exchanger 61 that is associated withthe device being in the stopped state is bypassed. Furthermore, in thesystem #4, in the case where both the cooling device 5 and the heatingdevice 6 of the system #4 are in the stopped state, the controller 4performs a control of causing at least one of the cooling-sideheat-medium flow adjusting valve 52 and the heating-side heat-mediumflow adjusting valve 62 to be closed, thereby stopping the supply ofwater to the system #4.

(Use of Exhaust Heat)

In Embodiment 5, when flowing into the cooling-side intermediate heatexchanger 51 of the cooling device 5, cooled water recovers exhaust heatfrom the cooling device 5, and is thus heated. Then, the water flows outof the cooling-side intermediate heat exchanger 51. The water that hasflowed out of the cooling-side intermediate heat exchanger 51 flows intothe heating-side intermediate heat exchanger 61 of the heating device 6,while being in the heated state.

Furthermore, when the water that has flowed out of the cooling-sideintermediate heat exchanger 51 flows into the heating-side intermediateheat exchanger 61, the water recovers exhaust heat from the heatingdevice 6, and is thus cooled. Then, the water flows out of theheating-side intermediate heat exchanger 61. The water that has flowedout of the heating-side intermediate heat exchanger 61 flows into therelay unit 3 as return water, while being in the cooled state.

As described above, in the system #4 in which the cooling device 5 andthe heating device 6 are connected in series, exhaust heat from thecooling device 5 is used by the heating device 6. Thus, the heatexchange efficiency of the heating device 6 is improved. Furthermore,exhaust heat from the heating device 6 cools return water to the relayunit 3, thus assisting cooling of water in the relay unit 3 andimproving the energy efficiency of the entire system for energy saving.

In the case where the cooling device 5 cannot achieve required operatingperformance only with heat exchange performed by the cooling-sideintermediate heat exchanger 51, a cooling-side auxiliary heat exchangermay be provided upstream or downstream of the cooling-side intermediateheat exchanger 51 in the cooling refrigerant circuit such that thecooling-side auxiliary heat exchanger is connected in series to thecooling-side intermediate heat exchanger 51. Because of provision ofsuch a configuration, the amount of heat exchange that is insufficientin the case where the heat exchange is performed at the cooling-sideintermediate heat exchanger 51 only is compensated for the amount ofheat exchange at the cooling-side auxiliary heat exchanger, and thecooling device 5 can thus achieve the required operating performance.

However, in the case where the cooling-side auxiliary heat exchanger isprovided upstream of the cooling-side intermediate heat exchanger 51,and the cooling device 5 can achieve the required operating performanceonly with the cooling-side intermediate heat exchanger 51, it ispreferable that a cooling-side auxiliary bypass pipe that bypasses thecooling-side auxiliary heat exchanger be provided. This is because whenheat exchange is not performed using the cooling-side auxiliary heatexchanger, the amount of heat transferred to water during heat exchangeperformed using the cooling-side intermediate heat exchanger 51 isincreased, and use of exhaust heat by the heating device 6, which islocated downstream of the cooling device 5, can be improved.

On the other hand, in the case where the cooling-side auxiliary heatexchanger is provided downstream of the cooling-side intermediate heatexchanger 51, it is not necessary to provide the cooling-side auxiliarybypass pipe. That is, in the case where the shortage of the amount ofheat exchange performed using the cooling-side intermediate heatexchanger 51 is compensated for the amount of heat exchange using thecooling-side auxiliary heat exchanger, the cooling-side auxiliary heatexchanger may be used.

Furthermore, in the case where the heating device 6 cannot achieve therequired operating performance only with heat exchange performed usingthe heating-side intermediate heat exchanger 61, a heating-sideauxiliary heat exchanger may be provided upstream or downstream of theheating-side intermediate heat exchanger 61 such that the heating-sideauxiliary heat exchanger is connected in series to the heating-sideintermediate heat exchanger 61. Because of provision of such aconfiguration, the amount of heat exchange that is insufficient in thecase where the heat exchange is performed using the heating-sideintermediate heat exchanger 61 only is compensated for the amount ofheat exchange using the heating-side auxiliary heat exchanger, and theheating device 6 can thus achieve the required operating performance.

However, in the case where the heating-side auxiliary heat exchanger isprovided upstream of the heating-side intermediate heat exchanger 61,and the heating device 6 can achieve the required operating performanceusing the heating-side intermediate heat exchanger 61 only, it ispreferable that a heating-side auxiliary bypass pipe that bypasses theheating-side auxiliary heat exchanger be provided. This is because inthe case where heat exchange is not performed using the heating-sideauxiliary heat exchanger, the amount of heat transferred to water duringheat exchange performed using the heating-side intermediate heatexchanger 61 is increased, and use of exhaust heat in return water canbe improved.

On the other hand, in the case where heating-side auxiliary heatexchanger is provided downstream of the heating-side intermediate heatexchanger 61, it is not necessary to provide the heating-side auxiliarybypass pipe. That is, in the case where the shortage of the amount ofheat exchange performed using the heating-side intermediate heatexchanger 61 is compensated for the amount of heat exchange performedusing the heating-side auxiliary heat exchanger, the heating-sideauxiliary heat exchanger may be used.

(Case where Heat Recovery and Another Heat Recovery are Balanced)

The balance between heat recovery by the cooling-side intermediate heatexchanger 51 and that by the heating-side intermediate heat exchanger 61will be described. In the case where a water circulation passage inwhich only the system #4 is connected to the relay unit 3 is providedby, for example, a control of inhibiting water from flowing into thesystem #1, when heat recovered by the cooling-side intermediate heatexchanger 51 and heat recovered by the heating-side intermediate heatexchanger 61 are balanced, the operation of the outdoor unit 1 may bestopped. That is, heat exchange between the cooling device 5 and theheating device 6 can be carried out simply by an operation of drivingthe pump 33 of the heat medium circuit to cause water to circulate inthe system #4, and an energy saving operation can thus be performed. Itshould be noted that the case where “heat recovery and another heatrecovery are balanced” is not limited to the case where the inlettemperature and the outlet temperature of water are equal to each otherin a system where the cooling device 5 and the heating device 6 areconnected in series. For example, the above case also covers the casewhere heat recovery and another heat recovery are substantially balancedas in the case where the difference between the temperature of waterthat flows into the system #4 and the temperature of water that flowsout of the system #4 is not great, and the influence of a change intemperature is thus small in the entire heat medium circuit.Furthermore, the above case also covers the case where the heat recoveryand another heat recovery are balanced even in the case where thetemperature of water changes at any portion of the heat medium circuit,for example, in the case where the temperature of water changes becauseof heat exchange between outside air and water during circulation of thewater through the heat medium pipe 20.

(Case where Heat Recovery and Another Heat Recovery are not Balanced)

For example, when the indoor units 2 of the system #1 perform theheating operation, and the amount of heat transferred to water at thecooling-side intermediate heat exchanger 51 is larger than the amount ofheat received from water at the heating-side intermediate heat exchanger61, water that flows out of the system #4 has a high temperature. Thatis, when the temperature of water that flows out of the system #4 ishigher than the temperature of water that flows into the system #4,return water to the relay unit 3 has a high temperature. Therefore, theoperating frequency of the compressor 11 or the rotation speed of a fanthat sends air to the heat-source-side heat exchanger 13 may be reducedto reduce the load on the outdoor unit 1.

On the other hand, when the indoor units 2 of the system #1 perform thecooling operation, and the temperature of water that flows out of thesystem #4 is higher than the temperature of water that flows into thesystem #4, return water to the relay unit 3 has a high temperature. Itis therefore necessary to increase the load on the outdoor unit 1. Asdescribed above, in order to maintain the operating state of the system#1, it is necessary to control the load on the outdoor unit 1 based onthe operating state of the indoor units 2 of the system #1 and thetemperatures of water that flows into and flows out of the system #4.

In view of the above, in Embodiment 5, when heat recovery by thecooling-side intermediate heat exchanger 51 and that by the heating-sideintermediate heat exchanger 61 are not balanced, the load on the outdoorunit 1 is adjusted based on the operating states of the indoor units 2of the system #1 and the temperatures of water that flows into and flowsout of the system #4.

FIG. 23 is a flowchart illustrating an example of the flow of processingin the case where heat recovery by the cooling-side intermediate heatexchanger 51 and that by the heating-side intermediate heat exchanger 61in Embodiment 5 are not balanced. First, in step S1, the controller 4determines whether or not the indoor units 2 of the system #1 are in theheating operation.

In the case where the indoor units 2 are in the heating operation (Yesin step S1), in step S2, the controller 4 compares the inlet temperatureof water in the system #4 that is detected by the inlet temperaturesensor 56 and the outlet temperature of water in the system #4 that isdetected by the outlet temperature sensor 67 with each other. As theresult of the comparison, when the inlet temperature in the system #4 ishigher than the outlet temperature in the system #4 (Yes in step S2), instep S3, the controller 4 controls components in the outdoor unit 1,such as the compressor 11, and components in the relay unit 3, toincrease the load on the outdoor unit 1 in order to increase the amountof heat exchange at the intermediate heat exchanger 32. By contrast,when the inlet temperature in the system #4 is lower than or equal tothe outlet temperature in the system #4 (No in step S2), the state ofreturn water that flows out of the system #4 is a state in which heat isaccumulated in the return water. Therefore, in step S4, the controller 4controls the components of the outdoor unit 1 and the relay unit 3 toreduce the load on the outdoor unit 1 in order to reduce the amount ofheat exchange at the intermediate heat exchanger 32.

Furthermore, in step S1, when the indoor units 2 are in coolingoperation (No in step S1, in step S5, the controller 4 compares theinlet temperature of water in the system #4 and the outlet temperatureof water in the system #4 with each other. As the result of thecomparison, when the inlet temperature in the system #4 is lower than orequal to the outlet temperature in the system #4 (No in step S5), thecontroller 4 controls in step S6, the components in the outdoor unit 1and in the relay unit 3 to increase the load on the outdoor unit 1 inorder to increase the amount of heat exchange in the intermediate heatexchanger 32. By contrast, when the inlet temperature in the system #4is higher than the outlet temperature in the system #4 (Yes in step S5),the state of return water that flows out of the system #4 is a statewhere heat is accumulated in the return water. Therefore, in step S7,the controller 4 controls the components in the outdoor unit 1 and inthe relay unit 3 to reduce the load on the outdoor unit 1 in order toreduce the amount of heat exchange in the intermediate heat exchanger32.

Next, in step S3 or step S6, in the case where the load on the outdoorunit 1 is increased, in step S8, the controller 4 makes a comparisonbetween the amount of increase in electric power in the outdoor unit 1that is caused by increase in the load and the amount of decrease inelectric power in the heat medium circuit, i.e., in the cooling device 5and the heating device 6 that is caused by use of exhaust heat in thesystem #4. As the result of the comparison, when the amount of increasein electric power in the outdoor unit 1 is larger than the amount ofdecrease in electric power in the heat medium circuit (Yes in step S8),in step S9, the controller 4 returns the load on the outdoor unit 1 thatis increased in step S3 or step S6 to an original load. Then, in stepS10, the controller 4 controls the opening degree of the cooling-sideheat-medium flow adjusting valve 52 or the heating-side heat-medium flowadjusting valve 62 to cause the cooling-side intermediate heat exchanger51 or the heating-side intermediate heat exchanger 61 in the system #4to be bypassed.

To be more specific, when the load on the outdoor unit 1 is increased(step S3) because the indoor units 2 are in heating operation and theinlet temperature of water in the system #4 is higher than the outlettemperature of water in the system #4, the controller 4 controls theopening degree of the heating-side heat-medium flow adjusting valve 62to cause the heating-side intermediate heat exchanger 61 to be bypassed.As described above, when the outlet temperature is low during heatingoperation, the heating-side intermediate heat exchanger 61 is bypassedto reduce heat to be received, while maintaining heat to be transferred.Furthermore, when the load on the outdoor unit 1 is increased (S6)because the indoor units 2 are in cooling operation and the inlettemperature of water in the system #4 is lower than or equal to theoutlet temperature of water in the system #4, the controller 4 controlsthe opening degree of the cooling-side heat-medium flow adjusting valve52 to cause the cooling-side intermediate heat exchanger 51 to bebypassed.

On the other hand, when the amount of increase in electric power in theoutdoor unit 1 is lower than or equal to the amount of decrease inelectric power in the heat medium circuit (No in step S8), in step S11,the controller 4 maintains the load on the outdoor unit 1 increased instep S3 or step S6.

As described above, in Embodiment 5, the load on the outdoor unit 1 isadjusted based on the operating states of the indoor units 2, thetemperature of water that flows into the system #4, and the temperatureof water that flows out of the system #4. It is therefore possible tocause the cooling device 5 and the heating device 6 to sufficientlyachieve operating performance, and also possible to reduce electricpower required for the operation of the entire air-conditioningapparatus 500. In this case, steps S8 to S11 are not indispensable. Asindicated in FIG. 23, the load on the outdoor unit is controlled onlybased on the comparison between the inlet temperature and the outlettemperature in the system #4, but may be controlled also inconsideration of the difference between temperatures of water in anothersystem or a change in temperature of water in the pipe.

Regarding this example, although it is described above that when theamount of increase in electric power in the outdoor unit 1 is largerthan the amount of decrease in electric power in the heat mediumcircuit, the cooling-side intermediate heat exchanger 51 or theheating-side intermediate heat exchanger 61 is bypassed in step S10.This, however, is not limiting. For example, the cooling-sideintermediate heat exchanger 51 or the heating-side intermediate heatexchanger 61 may not be bypassed.

In the case where the cooling-side intermediate heat exchanger 51 or theheating-side intermediate heat exchanger 61 is bypassed, an increase inelectric power in the entire air-conditioning apparatus 500 is reduced.This is thus effective from an electrical point of view. By contrast, inthe case where the cooling-side intermediate heat exchanger 51 or theheating-side intermediate heat exchanger 61 is not bypassed, exhaustheat in the cooling device 5 can be used by the heating device 6. Thisis thus effective from a thermal point of view. Therefore, whether thecooling-side intermediate heat exchanger 51 or the heating-sideintermediate heat exchanger 61 is bypassed or not may be determined asappropriate in consideration of a desired advantage to be obtained whenthe cooling-side intermediate heat exchanger 51 or the heating-sideintermediate heat exchanger 61 is bypassed or not bypassed. Furthermore,water may be partially caused to bypass the cooling-side intermediateheat exchanger 51 or the heating-side intermediate heat exchanger 61.That is, in order to reduce the difference between the inlet temperatureof water in the system #4 and the outlet temperature of water in thesystem #4, the distribution of water to the intermediate heat exchangerand the bypass passage may be controlled by the cooling-side heat-mediumflow adjusting valve 52 or the heating-side heat-medium flow adjustingvalve 62. In this case, it is possible to recover exhaust heat whilereducing an increase in electric power in the outdoor unit 1.

In the case where the cooling-side intermediate heat exchanger 51 isbypassed, the cooling refrigerant in the cooling device 5 is notsufficiently condensed, and thus, as described above, it is necessary toprovide and connect the cooling-side auxiliary heat exchanger in seriesto the cooling-side intermediate heat exchanger 51. Furthermore, in thecase where the heating-side intermediate heat exchanger 61 is bypassed,the heating refrigerant in the heating device 6 is not sufficientlyevaporated, and thus, as described above, it is necessary to provide andconnect the heating-side auxiliary heat exchanger in series to theheating-side intermediate heat exchanger 61.

Moreover, in this example, whether the changed load on the outdoor unit1 is returned or not is determined based on the comparison between theamount of increase in electric power in the outdoor unit 1 and theamount of decrease in electric power in the heat medium circuit. Inaddition to this, the amount of change in electric power in the coolingdevice 5 and the heating device 6 may be considered.

Although it is not referred to in the above description, in theair-conditioning apparatus 500, as in Embodiments 1 to 4, a flow-ratecontrol process is performed to cause water to flow at a required flowrate, through the FCUs 21 a to 21 c, the cooling device 5, and theheating device 6. That is, in the air-conditioning apparatus 500, theopening degrees of the heat-medium flow adjusting valves 22, thecooling-side heat-medium flow adjusting valve 52 and the heating-sideheat-medium flow adjusting valve 62 that are associated with the FCUs 21a to 21 c, respectively, are controlled. Thus, the flow rates of waterfor the FCU 21 a to 21 c, the cooling-side intermediate heat exchanger51 and the heating-side intermediate heat exchanger 61 are adjustedbased on required performance for the FCUs 21 a to 21 c, thecooling-side intermediate heat exchanger 51 and the heating-sideintermediate heat exchanger 61.

In Embodiment 5, the cooling device 5 and the heating device 6 in thesystem #4 may be interchanged with each other. To be more specific, theheating device 6 may be provided on the upstream side in the flow ofwater in the system #4, and the cooling device 5 may be provided on thedownstream side in the flow of water in the system #4. Furthermore, thenumbers of cooling devices 5 and heating devices 6 connected in seriesin the system #4 are not limited to the numbers described aboveregarding this embodiment, and a plurality of cooling devices 5 and aplurality of heating devices 6 may be connected in series.

Furthermore, the cooling-side bypass pipe 50 of the cooling device 5 andthe heating-side bypass pipe 60 of the heating device 6 can be omitted.In this case, when water is caused to flow through the cooling-sideintermediate heat exchanger 51, with the cooling device 5 being in thestopped state, water flows through the cooling-side intermediate heatexchanger 51 without exchanging heat. Thus, it is possible to obtain anadvantage equivalent to that in the case where the cooling-sideintermediate heat exchanger 51 is bypassed. Also, when water is causedto flow through the heating-side intermediate heat exchanger 61, withthe heating device 6 being in the stopped state, water flows through theheating-side intermediate heat exchanger 61 without exchanging heat.Thus, it is possible to obtain an advantageous effect substantiallyequal to an advantage equivalent to that in the case where theheating-side intermediate heat exchanger 61 is bypassed.

However, when water passes through the cooling-side intermediate heatexchanger 51 or the heating-side intermediate heat exchanger 61, someloss and pressure loss due to transfer of heat occur at the cooling-sideintermediate heat exchanger 51 and the heating-side intermediate heatexchanger 61. Therefore, it is preferable that the cooling-side bypasspipe 50 and the heating-side bypass pipe 60 be provided.

In the cooling device 5 from which the cooling-side bypass pipe 50 isomitted, the cooling-side heat-medium flow adjusting valve 52 does notneed to have a plurality of outflow ports, and has only to have afunction of adjusting the flow rate of water that flows into thecooling-side heat-medium flow adjusting valve 52 and allowing the waterto flow out at the adjusted flow rate. Similarly, in the heating device6 from which the heating-side bypass pipe 60 is omitted, theheating-side heat-medium flow adjusting valve 62 does not need to have aplurality of outflow ports, and has only to have a function of adjustingthe flow rate of water that flows into the heating-side heat-medium flowadjusting valve 62 and allowing the water to flow out at the adjustedflow rate.

In this example, the system #4 includes the cooling device 5 and theheating device 6 that are connected in series, and the system #4 isconnected parallel to the system #1. This, however, is not limiting. Forexample, the system #4 may include the cooling device 5 only. In thiscase, the load on the outdoor unit 1 and the flow of water in the system#4 are controlled based on the operating state of the system #1.

In the case where the indoor units 2 of the system #1 are in heatingoperation, the temperature of water that flows out of the cooling device5 of the system #4 is higher than the temperature of water that flowsinto the cooling device 5 and return water to the relay unit 3 thus hasa high temperature. Therefore, the load on the outdoor unit 1 may bereduced. Thus, the controller 4 performs a control of causing the loadon the outdoor unit 1 to be reduced. Therefore, the electric powerrequired for the entire air-conditioning apparatus 500 can be reduced.

By contrast, in the case where the indoor units 2 of the system #1 arein cooling operation, the temperature of water that flows out of thecooling device 5 of the system #4 is higher than the temperature ofwater that flows into the cooling device 5 and return water to the relayunit 3 thus has a high temperature. Therefore, it is necessary toincrease the load on the outdoor unit 1. However, when the control ofincreasing the load is performed, the electric power required for theentire air-conditioning apparatus 500 is increased. In view of theabove, in this case, water that flows into the cooling device 5 isblocked. Thus, the load on the pump 33 is reduced and the energyefficiency can thus be improved for energy saving.

In such a case, in the cooling device 5, cooling refrigerant cannot becondensed by the cooling-side intermediate heat exchanger 51. Therefore,as described above, the cooling-side auxiliary heat exchanger isconnected in series to the cooling-side intermediate heat exchanger 51,and cooling refrigerant is condensed by the cooling-side auxiliary heatexchanger.

A control depending on whether the above cooling-side auxiliary heatexchanger is provided or not may be performed. That is, as indicated inFIG. 23, when the indoor units 2 are in heating operation (Yes in stepS1), the controller 4 compares the temperature of water that is detectedby the inlet temperature sensor 56 of the cooling device 5 and thetemperature of refrigerant that is detected by a discharge temperaturesensor provided in the compressor. In the case where the cooling device5 includes a cooling-side auxiliary condenser, when the temperature ofwater is higher than the temperature of refrigerant, the controller 4may perform a control of causing water to flow through the cooling-sidebypass pipe 50 to allow the cooling device 5 to be operatedsubstantially by the cooling-side auxiliary condenser only. By contrast,in the case where the cooling device 5 does not include the cooling-sideauxiliary condenser, the cooling device 5 cannot condense refrigerant.Therefore, when the temperature of water is higher than the temperatureof refrigerant, the controller 4 may cause the outdoor unit 1 to be inthe stopped state. Because of provision of such a configuration, it ispossible to prevent occurrence of a problem in which heat cannot betransferred from the refrigerant to water in the cooling-sideintermediate heat exchanger 51 when the temperature of the water ishigher than the temperature of refrigerant during heating operation.

Furthermore, in Embodiment 5, the system #4 may include the heatingdevice 6 only, and may be connected parallel to the system #1. Also inthis case, the load on the outdoor unit 1 and the flow of water in thesystem #4 are controlled based on the operating state of the system #1.

In the case where the indoor units 2 of the system #1 are in heatingoperation, the temperature of water that flows out of the heating device6 of the system #4 is lower than the temperature of water that flowsinto the heating device 6, and return water to the relay unit 3 thus hasa low temperature. Therefore, it is necessary to increase the load onthe outdoor unit 1. However, when the control of increasing the load isperformed, the electric power required for the entire air-conditioningapparatus 500 is increased. In view of the above, in this case, waterthat flows into the heating device 6 is blocked. Thus, the load on thepump 33 is reduced and the energy efficiency can be improved for energysaving.

By contrast, in the case where the indoor units 2 of the system #1 arein cooling operation, the temperature of water that flows out of theheating device 6 of the system #4 is lower than the temperature of waterthat flows into the heating device 6 and return water to the relay unit3 thus has a low temperature. Therefore, the load on the outdoor unit 1may be reduced. Accordingly, the controller 4 performs a control ofreducing the load on the outdoor unit 1. Thus, the electric powerrequired for the entire air-conditioning apparatus 500 can be reduced.

In such a case, in the heating device 6, heating refrigerant cannot beevaporated by the heating-side intermediate heat exchanger 61.Therefore, as described above, the heating-side auxiliary heat exchangeris connected in series to the heating-side intermediate heat exchanger61 of the heating device 6, and heating refrigerant is evaporated by theheating-side auxiliary heat exchanger.

In this case, the control depending on whether the heating-sideauxiliary heat exchanger is provided or not may be performed during theabove cooling operation. That is, in the case where the indoor units 2are in cooling operation (No in step S1), the controller 4 compares thetemperature of water that is detected by the inlet temperature sensor 66of the heating device 6 and the temperature of refrigerant that isdetected by the suction temperature sensor provided in the compressor.In the case where the heating device 6 includes a heating-side auxiliarycondenser, when the temperature of water is lower than the temperatureof refrigerant, the controller 4 may perform a control of causing waterto flow through the heating-side bypass pipe 60 to cause the heatingdevice 6 to be operated substantially by the heating-side auxiliarycondenser only. By contrast, in the case where the heating device 6 doesnot include the heating-side auxiliary condenser, the heating device 6cannot evaporate refrigerant. Therefore, when the temperature of wateris lower than the temperature of refrigerant, the controller 4 may causethe outdoor unit 1 to be in the stopped state. Therefore, it is possibleto prevent occurrence of a problem in which heat cannot be transferredfrom the refrigerant to the water in the cooling-side intermediate heatexchanger 51 when the temperature of water is lower than the temperatureof refrigerant during cooling operation.

Furthermore, in Embodiment 5, the cooling device 5 and the heatingdevice 6 may be included in respective systems, and the systems may beconnected parallel to the system #1. Also in this case, the load on theoutdoor unit 1 and the flow of water in each system are controlled basedon the operating state of the system #1.

In the case where the indoor units 2 of the system #1 are in heatingoperation, the temperature of water that flows out of the system of thecooling device 5 is higher than the temperature of water that flows intothe system of the cooling device 5 and return water to the relay unit 3thus has a high temperature. Furthermore, the temperature of water thatflows out of the system of the heating device 6 is lower than thetemperature of water that flows into the system of the heating device 6,and return water to the relay unit 3 thus has a low temperature.Therefore, the controller 4 performs a control of reducing the load onthe outdoor unit 1, and shutting out the flow of the water into thesystem of the heating device 6 or causing the water to bypass theheating-side intermediate heat exchanger 61.

By contrast, in the case where the indoor units 2 of the system #1 arein cooling operation, the temperature of water that flows out of thesystem of the cooling device 5 is higher than the temperature of waterthat flows into the system of the cooling device 5, and return water tothe relay unit 3 thus has a high temperature. Furthermore, thetemperature of water that flows out of the system of the heating device6 is lower than the temperature of water that flows into the system ofthe heating device 6, and return water to the relay unit 3 thus has alow temperature. Therefore, the controller 4 performs a control ofreducing the load on the outdoor unit 1, and blocking the flow of thewater into the system of the cooling device 5 or causing the water tobypass the cooling-side intermediate heat exchanger 51.

In such a manner, the load on the outdoor unit 1 and the flow of waterin each system are controlled based on the operating states of theindoor units 2 of the system #1, whereby the electric power required forthe entire air-conditioning apparatus 500 can be reduced, the load onthe pump 33 can be reduced, and the energy efficiency can be improvedfor energy saving. Also in this case, in the cooling device 5, thecooling refrigerant is condensed by the cooling-side auxiliary heatexchanger, and in the heating device 6, the heating refrigerant isevaporated by the heating-side auxiliary heat exchanger.

As described above, in the air-conditioning apparatus 500 according toEmbodiment 5, the cooling device 5 and the heating device 6 areconnected in series. Because of such a configuration, exhaust heat fromthe cooling device 5 is used by the heating device 6, and the heatexchange efficiency of the heating device 6 can thus be improved.Furthermore, since return water is cooled by exhaust heat from theheating device 6, and the energy efficiency of the entire system can beimproved for energy saving.

The cooling device 5 further includes the cooling-side bypass pipe 50that bypasses the cooling-side intermediate heat exchanger 51. Thus,when the cooling-side intermediate heat exchanger 51 does not cause heatexchange between water and the cooling refrigerant, water passes throughthe cooling-side bypass pipe 50. Therefore, the pressure loss and theloss due to transfer of heat can be reduced, compared with the casewhere water passes through the cooling-side intermediate heat exchanger51.

Furthermore, the cooling-side bypass pipe 50 is provided to extendthrough a region located outside of the cooling device 5. Thus, sincethe length of the cooling-side bypass pipe 50 is shortened, it ispossible to reduce the loss caused by transfer of heat, etc., when waterflows through the pipe.

Also, the heating device 6 includes the heating-side bypass pipe 60 thatbypasses the heating-side intermediate heat exchanger 61. Thus, when theheating-side intermediate heat exchanger 61 does not cause heat exchangeto be performed between water and the heating refrigerant, water passesthrough the heating-side bypass pipe 60. Therefore, it is possible toreduce the pressure loss and the loss caused by transfer of heat,compared with the case where water passes through the heating-sideintermediate heat exchanger 61.

Furthermore, the heating-side bypass pipe 60 is provided to extendthrough a region located outside the heating device 6. Thus, since thelength of the heating-side bypass pipe 60 is shortened, it is possibleto reduce the loss caused by transfer of heat when water flows throughthe pipe.

The cooling device 5 further includes a cooling-side auxiliary heatexchanger connected in series to the cooling-side intermediate heatexchanger 51 at a location upstream or downstream of the cooling-sideintermediate heat exchanger 51 in the cooling refrigerant circuit. Withsuch a configuration, the amount of heat exchange that is insufficientwhen the heat exchange is performed by the cooling-side intermediateheat exchanger 51 only is compensated for, and the cooling refrigerantcan thus be sufficiently condensed.

The cooling device 5 further includes a cooling-side auxiliary bypasspipe that bypasses the cooling-side auxiliary heat exchanger that isprovided upstream of the cooling-side intermediate heat exchanger 51.Thus, when the cooling device 5 can achieve required operatingperformance using the cooling-side intermediate heat exchanger 51 only,the cooling-side auxiliary heat exchanger can be bypassed.

The heating device 6 further includes a heating-side auxiliary heatexchanger connected in series to the heating-side intermediate heatexchanger 61 at a location upstream or downstream of the heating-sideintermediate heat exchanger 61 in the heating refrigerant circuit. Thus,the amount of heat exchange that is insufficient when the heat exchangeis performed at the heating-side intermediate heat exchanger 61 only iscompensated for, and the heating refrigerant can thus be sufficientlyevaporated.

The heating device 6 further includes a heating-side auxiliary bypasspipe that bypasses the heating-side auxiliary heat exchanger that isprovided upstream of the heating-side intermediate heat exchanger 61.Thus, in the case where the heating device 6 can achieve requiredoperating performance using the heating-side intermediate heat exchanger61 only, the heating-side auxiliary heat exchanger can be bypassed.

The air-conditioning apparatus 500 further includes the controller 4that adjusts the load on the outdoor unit 1 based on the operatingstates of the indoor units 2 of the system #1 and the temperatures ofwater that flows into and flows out of the system #4 in which thecooling device 5 and the heating device 6 are connected. When the indoorunits 2 are in heating operation, and the inlet temperature of waterthat flows into the system #4 is higher than the outlet temperature ofwater that flows out of the system #4, or when the indoor units 2 are incooling operation, and the outlet temperature in the system #4 is higherthan or equal to the inlet temperature in the system #4, the controller4 increases the load on the outdoor unit 1. Furthermore, when the indoorunits 2 are in heating operation, and the outlet temperature in thesystem #4 is higher than or equal to the inlet temperature in the system#4, or when the indoor units 2 are in cooling operation, and the inlettemperature in the system #4 is higher than the outlet temperature inthe system #4, the controller 4 reduces the load on the outdoor unit 1.Because of provision of such a configuration, it is possible to causethe cooling device 5 and the heating device 6 to sufficiently achieveoperating performance, and also possible to reduce the electric powerrequired for the operation of the entire air-conditioning apparatus 500.

Embodiment 6

Next, an air-conditioning apparatus according to Embodiment 6 of thepresent disclosure will be described. In Embodiment 6, the openingdegree of the heat-medium flow adjusting valves 22 are controlled toreduce the degree of deficiency in the starting performance of theindoor units 2 a to 2 i at the time when the indoor units 2 a to 2 istart their operation from the stopped state. Regarding Embodiment 6,components that are the same as Embodiment 1 will be denoted by the samereference signs, and their detailed descriptions will thus be omitted.

In Embodiment 6, the valve opening-degree determination unit 42 set theopening degrees of the heat-medium flow adjusting valves 22 in theindoor units 2 a to 2 i such that when all the indoor units 2 a to 2 iare in the stopped state, the heat-medium flow adjusting valves 22 allowwater that circulates in the heat medium circuit to flow through theindoor-side bypass pipes 23. To be more specific, the valveopening-degree determination unit 42 sets the opening degrees of all theheat-medium flow adjusting valves 22 such that the bypass openingdegrees are 100%, thereby causing the second outflow ports 22 c tocommunicate with the water outflow sides of the FCUs 21.

In such a manner, by controlling the opening degrees of the heat-mediumflow adjusting valves 22 such that water that circulates in the heatmedium circuit flows through the indoor-side bypass pipes 23, heat isaccumulated in water that is a heat medium. Thus, it is possible toperform precooling or preheating such that the temperature of water thatcirculates in the heat medium circuit reaches a temperature suitable forair conditioning, and it is therefore possible to reduce the degree ofdeficiency in the starting performance of the indoor units 2 a to 2 i atthe time when the indoor units 2 a to 2 i start their operations fromthe stopped state.

As described above, in the air-conditioning apparatus 100 according toEmbodiment 6, the valve opening-degree determination unit 42 sets theopening degrees of all the heat-medium flow adjusting valves 22 suchthat when the indoor units 2 a to 2 i are in the stopped state, theheat-medium flow adjusting valves 22 allow the second outflow ports 22 cand the water outflow sides of the FCUs 21 to communicate with eachother. Thus, heat is accumulated in water serving as the heat medium,and it is therefore possible to reduce the degree of deficiency in thestarting performance of the indoor units 2 a to 2 i at the time when theindoor units 2 a to 2 i start their operation from the stopped state.

Although the above descriptions are made with respect to Embodiments 1to 6 of the present disclosure, they are not limiting, and variousmodifications and applications can be made without departing from thescope of the present disclosure. For example, it is explained above thatthe outdoor unit 1 and the relay unit 3 are formed as separate units,but such an explanation is not limiting. The outdoor unit 1 and therelay unit 3 may be formed as a single body. Furthermore, Embodiments 1to 6 can be combined as appropriate.

Furthermore, it is explained above that the opening degree of theheat-medium flow adjusting valve 22 is determined based on FCUperformance, which can be found from various temperature information.However, this is also true of other examples. For example, the openingdegree of the heat-medium flow adjusting valve 22 may be determinedbased on information on whether each of the indoor units 2 is in thethermos-on state or the thermos-off state.

Moreover, a radiant panel may be used as a load-side unit. At theradiant panel, when a heat medium flows through a pipe of the radiantpanel, heat exchange is performed. Therefore, in the thermo-off state,the heat medium is caused to flow through a bypass pipe to inhibit theheat medium from flowing through the pipe of the radiant panel.

Furthermore, although it is described above that the pump 33 is providedin the relay unit 3, the description is not limiting. The pump 33 may beformed separate from the relay unit 3 as a pump unit, for example.

REFERENCE SIGNS LIST

-   -   1 outdoor unit 2, 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g, 2 h, 2 i        indoor unit 3 relay unit 4 controller 5 cooling device 6 heating        device 10 refrigerant pipe    -   11 compressor 12 refrigerant-flow switching device 13        heat-source-side heat exchanger 14 accumulator 20 heat medium        pipe 21, 21 a, 21 b, 21 c, 21 d, 21 e, 21 f, 21 g, 21 h, 21 i        fan coil unit 22 heat-medium flow adjusting valve 22 a inflow        port 22 b first outflow port 22 c second outflow port    -   22 d body 22 e opening-degree adjusting valve 22 f side wall 22        g partition wall 22 h opening port 23 indoor-side bypass pipe 24        inlet temperature sensor 25 outlet temperature sensor 26 suction        temperature sensor 27 indoor-side controller 31 expansion valve        32 intermediate heat exchanger 33 pump 41 FCU performance        calculation unit 42 valve opening-degree determination unit 43        valve control unit 44 heat-medium flow-rate determination unit        45 pump control unit 46 storage unit 50 cooling-side bypass pipe        51 cooling-side intermediate heat exchanger 52 cooling-side        heat-medium flow adjusting valve 52 a inflow port 52 b first        outflow port 52 c second outflow port 53 compressor 54 expansion        valve 55 use-side heat exchanger 56 inlet temperature sensor    -   57 outlet temperature sensor 58 suction temperature sensor 60        heating-side bypass pipe 61 heating-side intermediate heat        exchanger 62 heating-side heat-medium flow adjusting valve 62 a        inflow port 62 b first outflow port 62 c second outflow port 63        compressor 64 expansion valve 65 water heat exchanger 66 inlet        temperature sensor 67 outlet temperature sensor 68 heat medium        temperature sensor 71 hot water storage tank 72 water supply        pump 100, 200, 300, 400, 500 air-conditioning apparatus 121        use-side heat exchanger 122 fan

1. An air-conditioning apparatus comprising a cooling device; a heatingdevice; and a heat-medium circulation circuit in which a heat mediumcirculates, wherein the cooling device includes a cooling refrigerantcircuit in which cooling refrigerant circulates, and a cooling-sideintermediate heat exchanger configured to cause heat exchange to beperformed between the cooling refrigerant that flows in the coolingrefrigerant circuit and the heat medium, and also configured to operateas a condenser in the cooling refrigerant circuit, wherein the heatingdevice includes a heating refrigerant circuit in which heatingrefrigerant circulates, and a heating-side intermediate heat exchangerconfigured to cause heat exchange to be performed between the heatmedium and the heating refrigerant that flows in the heating refrigerantcircuit, and also configured to operate as an evaporator in the heatingrefrigerant circuit, and wherein the cooling device and the heatingdevice are connected in series in the heat-medium circulation circuit.2. The air-conditioning apparatus of claim 1, wherein the cooling devicefurther includes a cooling-side heat-medium flow adjusting valveconnected to an inflow side of the cooling-side intermediate heatexchanger, and configured to control a flow rate of the heat medium thatflows into the cooling-side intermediate heat exchanger, and the heatingdevice further includes a heating-side heat-medium flow adjusting valveconnected to an inflow side of the heating-side intermediate heatexchanger, and configured to control a flow rate of the heat medium thatflows into the heating-side intermediate heat exchanger.
 3. Theair-conditioning apparatus of claim 2, further comprising a controllerconfigured to control an opening degree of the cooling-side heat-mediumflow adjusting valve and an opening degree of the heating-sideheat-medium flow adjusting valve based on performance required for thecooling-side intermediate heat exchanger and performance required forthe heating-side intermediate heat exchanger, respectively.
 4. Theair-conditioning apparatus of claim 2, wherein the cooling-sideheat-medium flow adjusting valve has an inflow port through which theheat medium flows into the cooling-side heat-medium flow adjustingvalve, and a plurality of outflow ports through which the heat mediumflows out of the heat-medium flow adjusting valve at the adjusted flowrate, and the cooling device further includes a cooling-side bypass pipeconnected with at least one of the plurality of outflow ports andextending to bypass the cooling-side intermediate heat exchanger.
 5. Theair-conditioning apparatus of claim 2, wherein the heating-sideheat-medium flow adjusting valve has an inflow port through which theheat medium flows into the heating-side heat-medium flow adjustingvalve, and a plurality of outflow ports through which the heat mediumflows out of the heat-medium flow adjusting valve at the adjusted flowrate, and the heating device further includes a heating-side bypass pipeconnected with at least one of the plurality of outflow ports andextending to bypass the heating-side intermediate heat exchanger.
 6. Theair-conditioning apparatus of claim 1, wherein the cooling devicefurther includes a cooling-side auxiliary heat exchanger connected inseries to the cooling-side intermediate heat exchanger in the coolingrefrigerant circuit.
 7. The air-conditioning apparatus of claim 6,wherein the cooling device further includes a cooling-side auxiliarybypass pipe that extends to bypass the cooling-side auxiliary heatexchanger, and the cooling-side auxiliary heat exchanger is providedupstream of the cooling-side intermediate heat exchanger.
 8. Theair-conditioning apparatus of claim 6, wherein the cooling-sideauxiliary heat exchanger is provided downstream of the cooling-sideintermediate heat exchanger.
 9. The air-conditioning apparatus of claim1, wherein the heating device further includes a heating-side auxiliaryheat exchanger connected in series to the heating-side intermediate heatexchanger in the heating refrigerant circuit.
 10. The air-conditioningapparatus of claim 9, wherein the heating device further includes aheating-side auxiliary bypass pipe that extends to bypass theheating-side auxiliary heat exchanger, and the heating-side auxiliaryheat exchanger is provided upstream of the heating-side intermediateheat exchanger.
 11. The air-conditioning apparatus of claim 9, whereinthe heating-side auxiliary heat exchanger is provided downstream of theheating-side intermediate heat exchanger.
 12. The air-conditioningapparatus of claim 1, wherein an outdoor unit including a compressor anda heat-source-side heat exchanger, an intermediate heat exchanger, andan expansion valve are connected, thereby forming a refrigerant circuitin which refrigerant circulates, and the intermediate heat exchangercauses heat exchange to be performed between the refrigerant and theheat medium.
 13. The air-conditioning apparatus of claim 1, comprising aplurality of indoor units each of which includes an indoor-side heatexchanger configured to cause heat exchange to be performed between theheat medium and air, wherein an indoor unit system in which theplurality of indoor units are connected in series is connected parallelto a device system in which the cooling device and the heating deviceare connected in series.
 14. The air-conditioning apparatus of claim 13,wherein each of the plurality of indoor units further includes aheat-medium flow adjusting valve connected to an inflow side of theindoor-side heat exchanger and configured to control a flow rate of theheat medium that flows into the indoor-side heat exchanger.
 15. Theair-conditioning apparatus of claim 14, wherein the heat-medium flowadjusting valve has an inflow port through which the heat medium flowsinto the heat-medium flow adjusting valve, and a plurality of outflowports through which the heat medium flows out of the heat-medium flowadjusting valve at the adjusted flow rate, and the each indoor unitfurther includes an indoor-side bypass pipe connected with at least anyone of the plurality of outflow ports and extending to bypass theindoor-side heat exchanger.
 16. The air-conditioning apparatus of claim18, further comprising a controller configured to control a load on theoutdoor unit based on operating states of the plurality of indoor units,a temperature of the heat medium that flows into the device system, anda temperature of the heat medium that flows out of the device system.17. The air-conditioning apparatus of claim 16, wherein when theplurality of indoor units are in heating operation and an inlettemperature of the heat medium that flows into the device system ishigher than an outlet temperature of the heat medium that flows out ofthe device system, or when the plurality of indoor units are in coolingoperation and the outlet temperature is higher than or equal to theinlet temperature, the controller performs a control of increasing theload on the outdoor unit, and when the plurality of indoor units are inheating operation and the outlet temperature is higher than or equal tothe inlet temperature, or when the plurality of indoor units are incooling operation and the inlet temperature is higher than the outlettemperature, the controller performs a control of reducing the load onthe outdoor unit.
 18. The air-conditioning apparatus of claim 12,comprising a plurality of indoor units each of which includes anindoor-side heat exchanger configured to cause heat exchange to beperformed between the heat medium and air, wherein an indoor unit systemin which the plurality of indoor units are connected in series isconnected parallel to a device system in which the cooling device andthe heating device are connected in series.